Talk:Scuba diving/Archive 1

Merger proposal: Diving activities into Scuba diving

Does anybody else agree that Diving activities should be merged into Scuba diving? - Gr0ff

Endorse merge. — Swpb^talk|edits 19:38, 3 October 2007 (UTC)

Help Improve Wikipedia's coverage on SCUBA Diving

I am working on starting a WikiProject to improve the coverage on SCUBA diving. Add your name to the list of interested Wikipedians here: SCUBA WikiProject Proposal—Preceding unsigned comment added by Gr0ff (talk • contribs)

Injuries due to changes in air pressure

On looking at impressive this section again, I see that it gives only a selected list of injuries due to changes in air pressure. It's mainly about the importance of, and how to equalize, pressure changes. It needs to be rewritten.Robert P. O'Shea 09:03, 4 June 2007 (UTC)

OK--I've checked out the issue of rupture of the round window. In diving this can happen when the pressure in the middle ear is too low and the valsalva manoeuvre is too vigorous. The low pressure in the middle ear causes the typanic membrane (eardrum) to bulge in, putting pressure on the endolymph in the inner ear via the ossicular chain's pressing on the oval window. The round window bulges into the middle ear to relieve this pressure. The valsalva manoeuvre increases pressure in the venous system. This is communicated to the endolymph because it is contiguous with the venous system via the cochlear aqueduct and other avenues. The sudden increase in pressure of the endolymph can rupture the round window and also the oval window.Robert P. O'Shea 09:00, 4 June 2007 (UTC)

I changed some material, but I can be convinced otherwise (by citation). The version I changed referred to the possibility of inner ear injuries. But earlier in the article, it referred to a ruptured eardrum. The eardrum is part of the outer ear, or at least the interface between the outer and middle ears. I also deleted reference to a round window rupture. The round window is indeed part of the inner ear, but the inner ear is filled with fluid (endolymph) that should resist pressure changes better than air-filled spaces. I suppose it is possible for the round window to rupture along with the eardrum, but I've never heard of it.Robert P. O'Shea 07:44, 4 June 2007 (UTC)

• The full list is in Diving hazards and precautions. Anthony Appleyard 15:40, 4 June 2007 (UTC)

Under remodeling

I am currently completely redoing this article, so some articles may be deleted. Thank you, --Tvaughn 23:54, 2 May 2005 (UTC)

Breathing Underwater

I've added a lot to the Breathing underwater section, but it may be too much detail for this page. I think I need some help making it accessible as an intro... Cheers, --Arkayik 03:49, 19 May 2006 (UTC)

What is BCD a the end of the "Injuries due to changes in water pressure" section? Needs either a link or a expansion of the acronym. --Mycroft007 17:08, 21 December 2006 (UTC)

History Of Diving

Can someone please remove the arrows in the History Section? Thanks. --Tvaughn 00:21, 4 May 2005 (UTC)

This section has nothing to do with SCUBA diving. A history/development of SCUBA would surely be more relevant. Breathhold, diving bells, snorkelling and surface supply are not SCUBA because they are not self contained. . Perhaps a 'Diving (Underwater)' article should be added that covers all forms of underwater ambient pressure activity? It could replace the currently awful 'underwater diving' article. Any thoughts? TDIPete 14:36, 4 March 2007 (UTC)

A history of SCUBA could reasonably include breathhold and diving bells, as an evolutionary step toward SCUBA, though lengthy discussion of them should be avoided.Lsi john 14:19, 8 April 2007 (UTC)

I'm also not sure the section should be labeled 'History of Diving'. As this is a SCUBA article, technically it would be the 'History/Evolution of Scuba Diving' and probably should include a brief history of diving bells (etc) and then move into modern scuba and the developments for safety, etc.Lsi john 14:26, 8 April 2007 (UTC)

For the history of diving (scuba and otherwise), there is Timeline of underwater technology. Anthony Appleyard 07:54, 2 May 2007 (UTC)

This article needs a history section. The history section was removed without discussion (although the removal claims otherwise). Right now the article links to a timeline instead of a history, and does not provide any history section of it's own. Rather than being removed the section should have been repaired. HarryHenryGebel (talk) 16:50, 23 December 2007 (UTC)

I came to this page out of interest; the history section is extremely light on dates. and I think this is wrong. Can someone revise, perhaps with reference to the timeline page mentioned? Pwarne (talk) 05:20, 17 January 2013 (UTC)

Discussion

I would like to suggest that you add links to large scuba social networks or dive clubs. These web sites would provide valuable information to prospective and existing divers.

Also consider adding links to web sites with dive site listings.—Preceding unsigned comment added by Gadavis2 (talk • contribs) 16:28, 20 August 2008 (UTC)

It is worth reviewing the section AdSpam Policy and all of the sections concerning external links that follow it. In a nutshell, an encyclopedia article is not a repository for internet links, no matter how useful. If the sites referred to contain useful information, make an article or add the information (not the link) to a relevant existing page. Hope that helps. --RexxS (talk) 17:43, 20 August 2008 (UTC)

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Statements as the one that said narcosis could be controlled by someone, refer to what might happen in one case over some thousands (and I personally have in mind only one lucky case, in which an athlete was able to inflate his equilibre jacket - GAV - to reach the surface again from -75, but it has not been cleared yet if this was made volountarily).

Please, be wise in not creating false myths in a subject that has many references to death. Objectively, scuba diving can be dangerous if rules are not respected, and what in that sentence was completely out of a reasonable mature mentality of immersion.

Also, it might be advisable to specify that single "special scores" are not meant available to anyone's attempts. Records are achieved by highly athletic individuals, not by ordinary people.

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"Leonardo da Vinci affirmed in his Atlantic Code (Biblioteca Ambrosiana, Milan) that [etc.]."

Should it not rather be "Atlantic Codex"?
S.

Atlanticus Codex in Latin (Codex Atlanticus is the Italian habit for modern use of Latin and - perhaps - how it is classified in librarians' style, but it's a little less pure), Atlantic Code in English.

Choose one :-) [G]

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This page still needs some work. There is big difference between decompression sickness (the bends), nitrogen narcosis, and various emboli that can be sustained by rapid decompression. I'll work on it.
--Bob Jonkman, ACUC Level II instructor 903EA

I am very suspicious of the information in here. I think someone with minimal knowledge just wrote what they thought. I have corrected some of the more glaring errors. Someone with more detailed knowledge really needs to work on this. Bob Jonkman, are you still there? DJ Clayworth 14:49, 14 Aug 2003 (UTC) (P.S. does anyone actually have examples of people diving from kayaks, or ocean liners?)

SirScuba, do you have a reference for 'diving has fewer deaths than bowling'? It seems unlikely, simply because I find it hard to imagine a way in which you can kill someone while bowling.

Also, whoever is doing this, you need to leave a space after the external link before the closing bracket, or the external link doesn't work i.e. you need to write (mypage.html ) not (mypage.html). DJ Clayworth 17:57, 14 Aug 2003 (UTC)

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reply from sirscuba

dive kayaks http://www.sonic.net/~rocky/kayaks.htm

Ocean liners - there was a cruise ship "ocean spirit" ? that catered to divers, they launched inflatables to take the divers to the sites. I think they stop operation several years ago.

A few years ago a study was done, after crunching the numbers bowling was more dangerous than scuba, i see if i can find a link. Heart attack, choaking on food, slipping and falls, smoking, drinking, fights all happen at bowling alleys. I'll bet the number of death due to contact with a bowling ball are small.

The PADI Rescue Diver Manual (Copy write 1995 ISBN 1-878663-09-7) on page 30 in a side bar prints this "scuba ranks low in injury occurrence according to figures in the 1991 edition of the US National Safety Council accident facts. American Football comes in at 217 accidents per 10,000 participants annually Scuba Diving comes in at 4 per 10,000" "Activity injury incidence American Football 2.17% Baseball 2.09% Basketball 1.86% Football Soccer 0.91% Volleyball 0.37% Waterskiing 0.20% Racquetball 0.17% Tennis 0.12% Swimming 0.09% Bowling 0.04% Scuba Diving 0.04%" Please Note that this is for injuries not for deaths. As this is required reading for the PADI Rescue Diver Course this data might have been misrepresented and should be clarified. Fred Tittle PADI Master Scuba Diver Trainer 164579 SSI (Scuba Schools International) Dive Con Instructor 25265

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I removed 'embolia' from the list of diseases because it turns out that medically 'embolia' means The reduction of a limb dislocation] and is not the plural of embolism. Since I'm not sure that embolism was what the original author meant, I'm taking it out.

SirScuba, I think the quote about bowling is misleading. For a start you need to say per thousand what (per thousand hours spent doing the sport? per thousand people taking part?). I think it's also obvious to everybody that for any given person they are more likely to die from an hour spent doing Scuba than from an hour spent bowling. Insurance companies, who are usually very good at working out the statistics of these things, put scuba in a higher danger category than bowling (higher also than golf, basketball and jogging). Most of them put scuba in the same category as things like white water rafting and American Football, but lower than say hang-gliding or luge. Even then there is a depth limit of 25m. DJ Clayworth 15:58, 25 Aug 2003 (UTC)

For "obstruction", the singular is embolus and the plural is emboli. Anthony Appleyard 14:23, 12 Dec 2004 (UTC)

The statistic is based on number of injuries requiring a hospital visit per 10,000 participants per annum. Dont have one handy but I believe it is in chapter one of the Open Water (PADI) manual if some one wishes to verify TDIPete 13:59, 4 March 2007 (UTC)

Also of interest (includes table from US National Safety Council) Richardson, D. (1996). "An assessment of risk for recreational dive instructors at work". South Pacific Underwater Medicine Society journal reprinted from the Safe Limits Symposium held in Cairns, October 21-23 1994. 26 (2). ISSN 0813-1988. OCLC 16986801. Retrieved 2008-05-09. {{cite journal}}: Check date values in: |date= (help) Gene Hobbs (talk) 13:04, 9 May 2008 (UTC)

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OK - i removed the bowling reference & added verbage to the "death" comment

Two comments: first the topic of history should be history of diving rather than the history of SCUBA diving as much of the article is not related directly to SCUBA. Second: Whare the article discusses the development of metal helmets it should be changed so as not to reflect that these helmets were developed so that divers could go deeper and handel greater preassure. Helmets to not allow divers to go deaper. What helmets do is make a diver more comfertable, they provide safety (just like a construction worker who wares a hard hat) they do not somehow elminate the effects of preassure as implied by the article.

Need to see underwater

The article says: "Diving masks and diving helmets solve this problem. Occasionally commando frogmen use special contact lenses instead." Could someone give some more information about this? Google only gives links to people discussing the possiblity. Jarvik 23:30, 2 December 2005 (UTC)

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• Contact Lenses *

Commando frogmen will use these lenses in order to see underwater while eliminating the relatively large glass surface of a diving mask which can reflect light and give away the frogmans position.

200.233.51.145 16:26, 11 February 2006 (UTC)

Umm....Not exactly a great reference. While soft contact lenses are safe to wear while diving (with a mask), trying to use contact lenses as an alternative to a dive mask is pretty unpractical. Ignoring the fact that contacts don't cover the entire eye, there's the issue of keeping them in place. Water's a pretty dense substance, and swimming against a strong current or general wave surge would be more than enough to dislodge a contact lens -- and that's without taking the use of diver propulsion vehicles into consideration.

I don't know what the rest of the world's military divers are using, but I do know that the United States military has adopted Oceanic/Aeris's "Integrated Diver Display Mask". It's a very neat system, a basic "Heads-Up Display" that allows divers to monitor depth, bottom time, tank pressures and related information while leaving their hands free for other tasks. JEJoyce 11:28, 14 February 2006 (UTC)

The contact lenses referred to were first developed in the early 1960's. US patent #3,311,577 refers to magazine articles (e.g. Sports Illustrated) that detailed these lenses. This patent makes claims for a highly viscous saline solution to be used in conjunction with large diameter sclera contact lenses. Sclera lenses would remain in place with eyes open underwater, however they were quite uncomfortable. A topical anesthesia was sometimes applied. Two more recent patents related to improving this concept are US patent 5,831,713 and 6,048,063. The Navy encouraged these developments not so much for reducing reflections above water but rather for expanding the narrow field-of-view caused by conventional flat masks, which reduces situational awareness and the mission effectiveness of military "operators" (divers).Jon Kranhouse 09:12, 26 February 2007 (UTC)

They have been used by freedivers to prevent wasted air in mask equalisation, initially developed by Jaques Mayol if memory serves. I've never heard of them being used by the military. They would presumably need to be removed in order to be able to see clearly above water so would be a no-no for any mission which might possibly require surfacing. Also in polluted water or water with suspended particles (harbours or beach recon anyone?) they would be less than ideal. On top of that the possibility of them falling out (check out some of the freediving forums) seems to make them highly impractical for military applications. All sounds a bit James Bond to me. Oh, they also need to be custom made for individuals. TDIPete 13:45, 4 March 2007 (UTC)

Note regarding latest edits to 'Need to see'

I reverted the latest edits to this section because the new (much shorter) version did not adequately explain why the effect happens, nor why the mask helps correct it, IMO. It also incorrectly implies the reason for the distortion is that light traveling thru water causes it, vs. the correct reason that it is the interface between water and eye (vs. air and eye when outside the water or when wearing a mask) that creates the focusing problem. If I wanted to expand on this, I would mention that having a mask on is like looking inside a pond with a glassy surface, or looking inside an aquarium. Crum375 11:14, 11 June 2006 (UTC)

I made the amendments that you reversed. First, it's misleading to say that light travels slower in water than in air, because you're implying that the speed of light (i.e. signal velocity) is changed. It's only the phase velocity that's changed. I agree with you that my version's use of the world "through" is misleading, too, so perhaps it should be changed to say something like:

"Water has a higher refractive index than air. Light entering the eye from the water behaves differently than light entering from air. This creates a distortion that affects normal vision."

Second, an article on scuba diving should not go overboard on explaining refraction. A short explanation of the effects plus a link to the scientific article that details the phenomenon is more appropriate.

Third, I think that saying that the light will be focused is inaccurate. The air in the mask reverses the refraction, but has nothing to do with focusing light (i.e. act as a lens). gisarme 60.234.232.62 01:43, 18 June 2006 (UTC)

I agree with one point you make: that we should not go overboard in describing refraction per se. But I think I disagree on some of your other points, which I will try to explain. When an object emits light (normally by some type of reflection) within a given medium, a lens can focus the light rays to recreate a 2D rendition of the object on a surface (such as the eye's retina). The lens operates by refraction, and refraction is determined by the relative speeds of light (technically phase velocities) in the adjacent media. The reason a human's eye cannot focus clearly underwater is simply because the eye's lens is designed to focus (or refract) rays that arrive from an air medium into the eye's or lens' medium (actually a complex of several structures and media which I am simplifying for now), which is close to water in refractive index. Note that it is the difference between the refractive indices of the lens and the surrounding medium that determines (by Snell's Law) the actual refraction or bending of the light rays. When the light rays arrive from a water medium, the eye's effective refractive power is drastically reduced, since the lens and the surrounding medium are now so close in their refractive indices. This produces a focal plane well behind the retina and hence a very blurry 'off-focus' image on the retina itself. If we now introduce an air gap between the eye and the water medium, where the water-facing side of it is flat (similar to observing a flat-walled fish tank from outside), then that flat side will only produce a magnifying effect (which I will skip for now) but the rays entering the eye from the airgap will be properly refracted and focused since the difference between the lens and the medium is now back to 'topside' normal and hence the focal plane will fall into its normal location on the retina. Crum375 03:22, 19 June 2006 (UTC)

Refraction and underwater vision

1. Changed sub-head to more precisely address the topic and be consistent with other sub-heads (i.e. "Need to see" would be like "Need to breath" or "Need to not get the bends").

2. Refraction errors are reduced but not completely eliminated by flat dive masks. Added brief explanation of refractive distortions. This web page, not cited in article because of its business agenda, indeed has accurate details and illustrations:[1]

3. Deleted statement that a prescription “grind” can be put into a normal mask. Since 1987 the scuba industry in the USA has voluntarily agreed to use lens material at least as impact-resistant as tempered glass. The geometry of an Rx would violate the minimum thickness of this safety standard... but the tempered glass would break before a "grind" would even be possible. The shaping of a glass lens must be done before heat or chemical tempering. With CR-39 optical polymer, found on precious few masks, the grind would likewise violate minimum thickness requirements.

4. Brief addition of how generic and custom vision Rx is manufactured for modern masks.

5. Added brief info about a new type of dive mask, available since 2003, that expands underwater field-of-view almost 5X vs. all flat masks and eliminates refractive errors common to all flat masks. Statements in article are accurate and avoid "puffery." Besides the HydroOptix company’s claim for a true breakthrough in underwater vision, much validating information is available (e.g. the web’s most popular scuba forum: http://www.scubaboard.com). Jon Kranhouse 10:00, 26 February 2007 (UTC)

AdSpam Policy

• I am not sure what the 'official' WP policy is re AdSpam, but I know that all we want here is pure relevant sources to back up information in the article, and then perhaps some sites for 'further reading'. I think any site that proposes to sell anything (like equipment, trips etc.) should be almost automatically vetoed. Sites like DAN, PADI etc. in my opinion are eligible despite having some items for sale because they are so well known and focus on safety.

I think another issue should be a maximal link count - WP is not Google and does not supply links, except the most essential ones needed to understand the article. I think right now there are way too many links, and I would urge anyone to read through them and weed them down to the most essential per the above - the less non-essential links the better. My guess is that if some anon IP desperately tries to re-insert a removed link, while possibly removing competing links, that by definition is AdSpam. Crum375 21:29, 13 June 2006 (UTC)

• I went through the ads and chopped off some myself. If anyone truly believes that what appears on the surface as adspam is actually essential for this article, make a case here first, get a consensus to agree, and it will stay. Otherwise the ad will just be reverted by anyone who believes that these unnecessary commercials clutter the article. Thanks, Crum375 21:36, 13 June 2006 (UTC)
• As SCUBA diving has no central official sanctioning body, I agree that the main certification agencies (as SSI that was just anonymously added) should be retained as external links. Crum375 21:52, 7 July 2006 (UTC)
• As there is again a buildup of external links, I would strongly encourage any future contributor to that section to carefully review the external linking policy before doing so. Thanks, Crum375 15:01, 8 August 2006 (UTC)
• I am not spamming. I have no financial connection with these firms. The existence of these diving firms is a notable fact, whether or not they accidentally benefit from Wikipedia mentioning them. By this logic, JCB page better not point to the JCB firm's web site, and hundreds of similar examples. We are not in the years before Ralph Nader when public newspaper articles dared not mention a trade name, with a taboo of religious-type dreadedness. Anthony Appleyard 16:06, 8 August 2006 (UTC)
• I have again checked through these links. None is to an individual scuba gear dealer. Admittedly many of them are heavily loaded with advertisements to pay for the costs of running the web sites. It looks like that the previous editor merely chopped a length off the front of the list. Anthony Appleyard 16:14, 8 August 2006 (UTC)

• Anthony, I have no doubt in your sincerity, and I am not suggesting you are spamming, but I do suggest you read up on WP:EL. The issue is not just 'spam' per se in the form of commercial ads - it relates to all external links, even ones that sell nothing. Ideally, the perfect WP article should have no external links, or nearly none. The case you mention would be one of the few exceptions - a link pointing to a Web site belonging to the subject of the article is always acceptable and even recommended. In our case, the subject is an activity, so this does not directly apply. In general, the WP spirit is that any useful factual information in an external link should be incorporated (over time) into the main article, with a reference to the link if needed, and the external link then either disappears (if the info is also sourced elsewhere) or is moved into the direct reference list if cited. So again, please carefully review WP:EL, try to understand its spirit, and decide for yourself which of the external links you think are absolutely crucial and meet the WP:EL criteria. I'll refrain from reverting for now to give you a chance to work on it, although the better way is to work backwards by adding the crucial links. Thanks, Crum375 16:25, 8 August 2006 (UTC)

As a correction to my above message, even the case you mention would normally be no exception. In a case of a commercial site that belongs to the subject of the article, it would normally be cited as a reference, not as an external link. If it is cited as an external link that would still be OK, but unnecessary, as it would normally be better to have it as a reference. Crum375 16:31, 8 August 2006 (UTC)

Of course, ideally all the certification agencies mentioned would link to a corresponding Wiki page, which would then link externally, ergo those that insist on certain agencies should start appropriate Wiki page son those agencies, and then link from here to them :-) Rcnet 11:23, 22 November 2006 (UTC)

Training and certifying agencies

I added this section as I think it is very pertinent to Scuba diving. I also hope that by getting PADI et al. mentioned in this section, we can reduce the amount of external links. Per WP:EL we really should have a bare minimum of external links, but that's another ongoing issue that needs addressing. Anyone with time and knowledge (i.e. good sources) feel free to improve this section. Thanks, Crum375 14:45, 12 August 2006 (UTC)

I have added edit comments to that section to try to explain that these are strictly the most important internationally recognized certification agencies. I also think that each member of this list should have a well-sourced existing article explaining its prominence and its international recognition. Other agencies should possibly go to List of diver training organizations, if they otherwise qualify. Crum375 13:36, 25 March 2007 (UTC)

External links

I am quoting from WP:EL, what should not be included as External Link:

Any site that does not provide a unique resource beyond what the article here would have once it becomes an example of brilliant prose.

As I see it as a possibility that one day this article could become featured, I think we should aim in that direction starting today. Any external link added should be explained and justified carefully in this Talk page, per WP:EL criteria, or it can be removed by anyone, per WP policies and guidelines. Thanks, Crum375 14:56, 12 August 2006 (UTC)

Hello, would you please consider adding an external link to www.divebuddy.com. It's a free social network for divers that encourages diving with a buddy, dive safety, continued education, and staying active. The site is open to every type of diver from every agency. Thank you. Greg. —Preceding unsigned comment added by 98.194.34.132 (talk) 14:54, August 29, 2007 (UTC)

Fix first sentence

Anyone got some proposals for a rewrite of this?

Scuba diving is the term used to describe the use of a self-contained breathing set to stay underwater for periods of time greater than the average individual can breath-hold.

At least drop the last part "than the average individual can breath-hold" in the process, as it makes no sense - No one could ever even approximate the time differences involved. Rcnet 11:19, 22 November 2006 (UTC)

external link to canary diving adventures

hi everyone we are a dive center in gran canaria and we would like you to link to our web site, we are a Padi 5 star gold palm resort we recognise all dive organisations & qualifications, but mainly teach Padi, we do all courses from beginners in our pool right up to dive master, we are based in the bay of taurito a small secluded bay in gran canaria next door to a 4 star hotel of which all our guests are welcome to use the faciilities whilst waiting to dive, in return for a link we would like to offer discount to all the readers of your site, thank you Sam [2] sam@canary-diving.com Crambo 11:07, 11 January 2007 (UTC)

Sam, thank you for the information about your business. Unfortunately, Wikipedia is not the Yellow Pages, and we cannot link to your site from here, see also our external link guideline. Thanks for understanding, Crum375 12:38, 11 January 2007 (UTC)

external link to ABC of Diving

Hello there... I have included a link to 'ABC of diving' in this page sometime ago and before that I'm a regular watcher,observer, and contributor that is, aiming to remove the tag that was placed in this page so it to conform to every standards (standards, that is, that should just to used as a BASIS) needed. And in my surprise "ABC's of Diving - Basics of going scuba diving" is no longer available in the External links section. Before one should say things "like please stop adding ads as external links or cert schools - see Talk" AND "Rvt - please discuss on Talk page" -> Crum375. I would suggest that this website be seen first before posting any word. As I've said I'm appealing to each and every contributors who in one way or another knows how to really value and see what QAULITY, CONTENT and IMPORTANCE mean using their human understanding with the help of a guideline which should JUST be used merely as a GUIDELINE and not supposed to be in full control of ones human understanding. Thank you! Reader contributor 12:20 PM, 15 March 2007

Please see the "AdSpam policy - again" section below. Thanks, Crum375 04:25, 15 March 2007 (UTC)

The reason it keeps getting deleted is that it has a store or links to stores which is promotion and reads like an advert rather than pure unbiased information about diving if that helps you at all. Darthgriz⁹⁸ 04:27, 15 March 2007 (UTC)

Endorse Removal of link as it has become apparent that it is part of a pattern of spam from User:Reader contributor. From his/her user page, it is apparent that s/he works for the company responsible for the website that s/he keeps spamming into articles. Please see WP:COI and WP:EL on why a link to a commercial website that you are trying to promote keeps getting deleted. Leuko 04:32, 15 March 2007 (UTC)

I call spam as well. Spartaz ^Humbug! 07:07, 15 March 2007 (UTC)

Scuba flags

Ok, I don't want to just delete these so I'm going to ask, why are there random scuba flags scattered throughout the article? Is somebody diving there? (never mind bad diver joke) But it just seems that the article only needs one, or maybe two but different flags such as the blue one and the red one, but not 4 red ones or what ever number is there now. Darthgriz⁹⁸ 02:11, 7 February 2007 (UTC)

Good catch. Someone must have snuck them in ;^) Crum375 02:54, 7 February 2007 (UTC)

Changing 'SCUBA Flag' to 'divers down' flag as it denotes any diving operation not just Scuba.TDIPete 14:14, 4 March 2007 (UTC)

AdSpam policy - again

There is a constant barrage of various promoters of commercial sites that are trying to use Wikipedia as an advertising vehicle. Please read WP:EL, WP:NOT, etc. This article is about Scuba Diving, and it should remain an encyclopedic description of that topic. As a reference point, go check EB and see how many ads it carries on its Scuba Diving entry. Please refrain from adding advertising materials here. Thanks, Crum375 03:44, 15 March 2007 (UTC)

For convenience, I am pasting here from the old AdSpam section:

I am quoting from WP:EL, what should not be included as External Link:

Any site that does not provide a unique resource beyond what the article here would have once it becomes an example of brilliant prose.

As I see it as a possibility that one day this article could become featured, I think we should aim in that direction starting today. Any external link added should be explained and justified carefully in this Talk page, per WP:EL criteria, or it can be removed by anyone, per WP policies and guidelines. Thanks, Crum375 04:27, 15 March 2007 (UTC)

Going Metric

Many divers now work with metric measurements but this article is imperial only. I know that PADI (outside the US) is exclusively metric and by convention many books and guides on diving provide both imperial and metric measures for depths and pressures. This article contains both metric and imperial measurements but without any consistency. Is there a Wiki-wide convention on this or is it per article? In any case, this needs to be standardised. Narkboy 15:34, 8 May 2007 (UTC)

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In most cases, I see both units with one in parentheses, or one after the other. Most in the US are stilled trained and used to using the US measurements, so I think both should remain in the English versions. The US hasn't gone far in the last 20 years toward adopting metric for domestic use. I'm sure other language pages have edited to fit their normal readers use. I don't think anyone would mind if you put metric in where it may be missing now.Mbeatty 02:03, 9 May 2007 (UTC)

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OK, unless anyone has any objections, I'll edit the article to show "imperial (metric)" throughout - though Tvaughn mentioned he was redoing the entire article so I'll wait for a while. Narkboy 10:51, 9 May 2007 (UTC)

Scuba Diving Userbox

Here's another user box that you can use (esp. for those who are interested in this subject). Just copy this piece of code on your user page:

   {{User Scuba Diving}}

This will produce this:

This user enjoys scuba diving.

Cheers! Bu b0y2007 05:06, 19 May 2007 (UTC)

Interwiki correction

The interwiki to Portuguese in facts redirect to Diving, and not Scuba Diving as it's supposed to do. Please correct to pt:Mergulho Autônomo 13:34, 28 June 2007 User:Giulio.alfieri

• Wrong. pt:Mergulho says plenty about scuba diving, and page pt:Mergulho Autônomo does not exist. Anthony Appleyard 16:56, 28 June 2007 (UTC)
• You are partially correct. pt:Mergulho is about generic diving, including snorkeling, scuba and free diving. Moreover, that page need to be recycled because under the topic 'diving', extend explanation about scuba diving and history. The link I've put here in fact is wrong, the correct link to scuba diving in Portuguese is http://pt.wikipedia.org/wiki/Mergulho_aut%C3%B4nomo or pt:Mergulho_autônomo.

Merger proposal: Scuba set into Scuba diving

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the proposal was Reject Anthony Appleyard (talk) 06:43, 29 December 2007 (UTC)

• Reject: page Scuba set is about the technicalities of underwater breathing sets, and page Scuba diving is about scuba diving in general. Anthony Appleyard (talk) 17:27, 20 November 2007 (UTC)

The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Gas mixtures section and Narcosis

I edited the first paragraph to remove the words "...and nitrogen narcosis" in reference to EAN reducing that effect as I believe it is misleading. However, the edit was undone, so I need to clarify my reasoning.

Although I believe all will accept that a reduction in ppN2 will reduce nitrogen narcosis, the replacement by a different gas may not yield a reduction of narcotic potential in the resulting mix. Obviously replacement by helium produces a considerable reduction (hence I strongly disagree with the use of the term "inert gas narcosis" as it is most unhelpful).

There has been considerable debate for years about whether or not O2 is narcotic. If narcosis is correlated to the lipid solubility of a gas, then O2 should be at least as narcotic as N2 (O2 has a higher solubility). However, adsorption of O2 within the body may reduce this effect. I am unaware of any conclusive studies that prove the point one way or another.

So, it is possible that replacing N2 with O2 in a gas mix may, or may not, reduce its narcotic potential. As with all diving advice, we should be aiming to err on the side of caution. To make an unsubstantiated claim that EAN reduces narcosis leads to the danger of a diver overestimating his safe depth. The reverse leads to an underestimation and so should be the preferred advice until such time as the question of O2's narcotic potential is decided.

A secondary argument is that the main article Nitrox opens its second paragraph with the words "It is generally untrue that breathing nitrox can reduce the effects of nitrogen narcosis, as oxygen seems to have equally narcotic properties under pressure; thus one should not expect a reduction in narcotic effects due only to the use of nitrox." - at least let us have internal consistency within Wikipedia!

With that in mind I would request that the words "...and nitrogen narcosis" be removed from the first paragraph once more.

RexxS (talk) 00:43, 5 January 2008 (UTC)

Drysuits

Can I ask more experienced wikipedians for their advice on how best to improve the brief references to drysuits in the section "Avoiding losing body heat"? Would it be best to expand the present section or to create a new page entitled "Drysuits"?

I'm rather unhappy with the concept of "diver maneuverability" being the principle factor in distinguishing between types.

I was thinking that a comprehensive treatment would be in order for an encyclopaedia, to give a clearer picture of usage and advantages/disadvantages of the different types. I would suggest that there are effectively 3 different types of drysuit: Trilaminate (membrane); Neoprene; Crushed/Compressed Neoprene. This is because there are fundamental differences in insulation, buoyancy change, abrasion resistance and stretchability between the 3 types.

Perhaps some mention of typical ranges of water temperature that are considered suitable for drysuits, semis, wetsuits/shorties and skins would enhance this section if the detailed drysuit discussion were to be removed to a new page of its own?

RexxS (talk) 01:34, 5 January 2008 (UTC)

My apologies - I found the page entitled Dry suit (I was looking for Drysuits) which meets many of the points I raised above, although I'm still unhappy with the "diver maneuverability" idea being the main difference identified here, not least because it contradicts my own experience of using different types of drysuit. Is this the right thing to do in a section entitled "Avoiding losing body heat"? RexxS (talk) 01:49, 5 January 2008 (UTC)

My advice is to be BOLD; you seem to know a lot about the subject (this goes for the narcosis question as well), so if you want to write new (sourced) material (be it in an existing section, a new section, or a new article) or remove material you think is misleading or inaccurate, go for it. The burden of evidence is on the editor who adds a claim (such as the claim about decreased narcosis with nitrox), so if that claim isn't well-supported, you don't need approval from anyone on the talk page to remove it. Happy editing! — Swpb^talk.edits 18:03, 5 January 2008 (UTC)

Injuries due to changes in air pressure

I don't know how comprehensive we want to be, but there are certainly more than two means of "clearing the ears", not to mention combinations of them. In addition, the description of a Frenzel looks much more like a Toynbee to me (swallowing). Take a look at [3] and [4] for a couple of lists of methods.

What is best? - produce a list of own or give some references to external sites that do the job already? —Preceding unsigned comment added by RexxS (talk • contribs) 03:13, 7 January 2008 (UTC)

Request to insert a link to a large online diving resource

Hi All

Our company have just completed work on a large online diving resourse. I'd like tho add a link to it here as I think it's very relivent but want to check this is ok first. Should I create a wiki page on the site then link to the wiki page or place a link in the external links box? the site is Divemaster and is a online diving resourse run by divers for divers. Have a look over the site and let me know what you think.

Thanks

Ashley —Preceding unsigned comment added by Ashleypeake (talk • contribs)

• (Replied on user's talk page) — Swpb^{t & c} 14:45, 13 June 2008 (UTC)
• Hi Ashley, I took a look at your link - my compliments on a very nice site and I'm sure it has the potential to be a fine resource for divers, particularly UK ones like me! Although I can appreciate your enthusiasm for a fine project, I doubt that it would be correct to try to link to it from Wikipedia. Wikipedia is an encyclopedia and makes use of external sources only to verify the facts presented here. It is not a central portal intended to list external resources which may be of interest to the reader. The Scuba diving article has had a history of commercial interests attempting to drive traffic to their sales sites for their own benefit. This has led editors to quickly remove external links that direct to sites which sell goods or contain advertising. In your case, I can see that you feel that your site contains useful information and discussion fora which would interest divers. However, if your link were acceptable, where would we draw the line? The article could quickly turn into a list of "Online Diving Resources" as it would be easy for less-scrupulous contributors to add links to their own sites for purely selfish reasons. In any case, consider carefully what Swpb has said on your Talk page. Thank you for the courtesy of making an enquiry rather than just linking. --RexxS (talk) 00:11, 14 June 2008 (UTC)
• I looked quickly through the site and put the link in Scuba diving#External links. Anthony Appleyard (talk) 04:21, 14 June 2008 (UTC)

• Hi All,

  I've been working really hard to produce The Scuba Site - a scuba diving resource. I've been writing and paying experts to write specialised scuba diving locations and skills guides for it. Within 2 weeks I've got just over 100 visitors.

  Registered members can submit their own content, articles, news, upload photos or chat in the forum. I hope it's not considered "commercially biased", even though I've put 1 adsense block on there :)

  I think the unique content fares pretty well against other existing resources. 16:58, 21 November 2008 User:84.92.26.220

Hi all... I tried to log in to divemaster.com and have found that it is listed as for sale and no longer a functioning site. I would like to offer our new site in its place. we are dive critic and our mission is to promote a site by divers, for divers, about divers, where divers review dives, dive masters, dive equipment, and pretty much anything else you can think of that is dive related. We also have a forum attached that has gotten to 100 members in just 3 weeks of word of mouth. We are expecting to do a mass email to 18,000 divers to introduce them to our site and hope that it will be a place where everyone will go to be a dive critic!!! —Preceding unsigned comment added by Dispachcops (talk • contribs) 07:18, 31 March 2010 (UTC)

I'm afraid i don't think your site is an appropriate external link for the article, not least of all because it is so new. OwainDavies ^(about)_(talk) edited at 08:15, 31 March 2010 (UTC)

Request to promote diving as a leisure activity

• Hello Divers,

  I'd like tho add a link to it here as I think it's very relivent but want to check this is ok first. The site is Skaphandrus.com and is a online diving Site. The main objective of is to help promote diving as a leisure activity, not only to those who practice it, but also to the general public. To succeed on doing that, we have selected several areas where we believe there is a deficit of information and where we believe we can give a better contribution. Areas like Dive News, Dive Spots, Dive Entities, Marine Species, Shipwrecks and Underwater Photos are constantly updated at Skaphandrus. We at Skaphandrus will continuously thrive to keep the best information available to all the users spread in the world.

  Have a look over the site and let me know what you think.

  Thanks

  Luis Miguens _{10:43, 22 September 2008 User:213.58.174.9}

Request to insert a link for Worldwide Scuba Diving Directory & Map

Hi Divers

I can see there are some links to web directories already, however I think my resource will be very useful for people interested in scuba diving. On my web site - Worldwide Scuba Diving Directory & Map

We've combined a map based on Google Map's script and Web Directory. This combination allowes visitors to see information about all diving-related companies registered in the web directory. Because it is the biggest scuba diving related directory on the Web (it shows 5421 businesses but the ammount increases day by day) the map is the most precise and detailed. I've updated Google Map script so the map moves automatically to visitor's geographical point (using visitor's IP address) to make search easier. As well as this, we publish diving related news. The web site also includes detailed descriptions of the majority of the world's diving related businesses and organisations. Please, have a look over the site and let me know what you think.

Thanks, Alex —Preceding unsigned comment added by Divingfinder (talk • contribs) 00:15, 23 November 2008 (UTC)

The site certainly seems useful. With a Google page rank of 5 it is obviously well-visited and does not appear to be commercially-based. However, I'm still not convinced that these kind of external resources (useful as they may be) meet our criteria for external links, although I appreciate that this kind of interactive, map-based searching would not be able to be incorporated into the article. What do others think? --RexxS (talk) 02:21, 23 November 2008 (UTC)

Thank you. The web site also includes descriptions of the majority of the world's diving related businesses and organisations.Divingfinder (talk) 02:54, 23 November 2008 (UTC)

Image Resq89.jpg

This image is on Commons as PD with a website link as the source - yet doesn't appear on that website. The website link is also given as author. The anon IP posting it edit-warred by putting it on this page 4 times despite reversions (and managed to vandalise the article on 2 occasions as well) - all of this without a single edit summary. Frankly I don't see that it adds anything to the article. Given the uncertain provenance of the image and the way in which the IP has edit-warred, I'm going to remove it once more. If anyone can see any redeeming value in including the image, please feel free to discuss it here. --RexxS (talk) 13:43, 29 November 2008 (UTC)

Established community website for SCUBA Divers

A social networking website (like Facebook but just for divers) which has been running over a year now, so I would like to propose it's entry as an external link: www.blueflipperdiving.com[5] (BlueFlipper Diving).

All the usual social network activities like forums, sharing photos and videos, daily diving news, arranging trips, holidays, quizes with prizes, free web site for memebrs, etc, etc.

I wanted to share it on the discussion page to see if it was valid for adding, rather than just going ahead and trying to add it!! Many thanks, Simon. —Preceding unsigned comment added by 213.106.248.35 (talk) 12:14, 16 January 2009 (UTC)

Hi thanks for asking here first. It's a nice site and I'm sure many divers will find it valuable. However, in building our encyclopedia, we have agreed what is suitable for inclusion as external links. Clink on this link: WP:EL and have a look at what it has to say. I suspect your site may be excluded by WP:ELNO number 10. --RexxS (talk) 00:29, 17 January 2009 (UTC)

Time Underwater

There doesn't appear to be any detail on this page on typical times that are, or can be, spent underwater with scuba. I'd like to suggest that this be added... -Bernard S. Jansen (talk) 04:46, 29 June 2009 (UTC)

The time can be quite variable, depending on the amount of air in the cylinder, the depth of the dive and the rate that the diver uses air. There is more explanation at Diving cylinder#Measurements, but even that doesn't discuss all of the issues. I agree that a short description would be use full here, along with a link to the details in Diving cylinder. --RexxS (talk) 15:54, 29 June 2009 (UTC)

Indefinite semiprotection

Is there a good reason to have this article semiprotected indefinitely? Does this really attract so much vandalism that it couldn't be protected only for a few months at most? Nyttend (talk) 13:19, 13 August 2009 (UTC)

Rebreather without nitrogen

• I am not familiar with any scuba rebreathers (for depth greater than 20 feet or so) which do not use a diluting gas of some kind. Yet the unsourced paragraph which I removed says "Rebreathers do not have to carry nitrogen in addition to the oxygen, so they can be lighter while using the same amount of oxygen." If there is a reliable source which supports that, it should be provided. Please do not restore challenged material without appropriate sourcing. Per WP:V, "The burden of evidence lies with the editor who adds or restores material ... any material challenged ... must be attributed to a reliable, published source using an inline citation." Crum375 (talk) 22:59, 5 February 2010 (UTC)
• Of course, there are also rebreathers available that use helium as a diluent, but that's not the point. On open-circuit scuba, a typical one-hour recreational dive might use up about 5 lbs (2 kg) of air - the contents of an Al-80, for example. The weight of the gas is negligible compared to the 30 lbs (12 kg) of cylinder needed to carry it under high pressure. Since the rebreather re-uses most of the exhaled gas, the diver needs a much smaller - hence lighter - cylinder to have the same duration as a typical open-circuit rig. This ignores the fact that the weight of a bail-out cylinder and regulator needs to be factored in to the total weight of using a rebreather.

  Nevertheless, I agree that the content removed was way off the mark and would need to be re-written substantially to accurately reflect the facts. I'll try and dig out some sources comparing the weight and bulk of semi/closed-circuit gear vs open-circuit before attempting that. I'm pretty confident I know what should be written; but like you, I'd prefer to use verifiable sources than just write off the top of my head. --RexxS (talk) 03:26, 6 February 2010 (UTC)

• What you say makes sense. But I still don't see why this material (when correctly written and sourced) belongs in the "gas mixtures" section, and not in the "rebreather" section. Crum375 (talk) 03:40, 6 February 2010 (UTC)
• *Nor do I !! --RexxS (talk) 04:50, 6 February 2010 (UTC)

• I've sourced and rewritten the sentence on liquid breathing, so perhaps we don't need to include that part in this discussion? I suspect that the paragraph in contention was meant to be the final paragraph of the section above, but has become misplaced. It's effectively a summary of Rebreather#Advantages of rebreather diving, but that entire section relies principally on sourcing to Reynolds, Glen Harlan (December 2006), "Seeking New Depths", Popular Mechanics 183 (12), ISSN 0032-4558, and I can't use that to support any text here, as I don't have access to that source. I'll place the disputed text here and see if we can get a consensus on what we can write with sources:

Because compressed air is 78% nitrogen, much of the weight of air in conventional open-circuit scuba is nitrogen. Rebreathers do not have to carry nitrogen in addition to the oxygen, so they can be lighter while using the same amount of oxygen. Because the nitrogen in the system is kept to a minimum, decompressing is much less complicated than traditional SCUBA systems and, as a result, divers can stay down longer. Because rebreathers produce very few bubbles, they do not disturb marine life or make a diver’s presence known. This is very good for underwater photography.

--RexxS (talk) 07:54, 6 February 2010 (UTC)

• The first rebreathers, and for a long time the only rebreathers, were oxygen rebreathers, and that is what WWII frogmen used. Oxygen rebreathers are a fact. I have restored this paragraph, as:-

  Because compressed air is 78% nitrogen, much of the weight of air in conventional open-circuit scuba is nitrogen. Rebreathers do not have to carry as much nitrogen compared to the oxygen as there is in ordinary air, and some shallow-water rebreathers (oxygen rebreathers) carry only oxygen. As a result they can be lighter while using the same amount of oxygen. Because the nitrogen in the system is kept to a minimum, decompressing is much less complicated than traditional open-circuit scuba systems and, as a result, divers can stay down longer. Because rebreathers produce very few bubbles, they do not disturb marine life or make a diver’s presence known; this is useful for underwater photography, and for covert work.

  Anthony Appleyard (talk) 11:27, 6 February 2010 (UTC)

• I can source the first rebreathers (LARU and Amphibian) to http://archive.rubicon-foundation.org/dspace/bitstream/123456789/3987/1/ which also states the British Navy restricted O2 diving to 30 feet. I think we can all accept that pure O2 rebreathers are mainly only of historical interest.
  • Pure-oxygen rebreathers are still sold now, and I have seen them on naval diving gear makers' websites. There are still uses for them, when high ratio duration/bulk is needed and the frogmen / divers will not be going deep. Anthony Appleyard (talk) 14:31, 6 February 2010 (UTC)
• My twins carry 6000 litres of air, equivalent to about 2 hours of gentle diving at 20 metres (not on one dive of course!). The air weighs 7.5 Kg (6 Kg of nitrogen). But the cylinders weight about 34 Kg empty.
• A rebreather with two 2-litre 200-bar cylinders would be more than capable of the same duration (that's 400 litres of oxygen and we can assume about 1 litre per min actually consumed on a gentle dive). The weight of gas would be 500 g O2 and up to 500 g diluent (or 70 g if He is used). So we save 6.5 kg on weight of gas. But the pair of cylinders in the rebreather weigh at most 6 kg - that's a saving of 28 kg! Surely you must concede that a rebreather is lighter because it needs smaller cylinders, not because it has less nitrogen. As you can see, the weight of gases is just a tiny part of the saving. --RexxS (talk) 12:31, 6 February 2010 (UTC)
• What RexxS says makes sense to me, but whatever we end up adding to the article has to be a) reliably sourced and b) in the right section. This specific issue, once it's reliably sourced, seems to belong under "rebreather", not "gas mixes". I've removed the material again; per WP:V, challenged material should not restored or added without appropriate reliable sources provided via inline citation. Crum375 (talk) 13:24, 6 February 2010 (UTC)
• OK, OK, sorry :: I seem to need a reference that oxygen rebreathers exist. Oxygen rebreathers exist: hundreds of frogmen dived with them from WWII on until air scuba became more common for work diving, and after a long time mixture rebreathers became safer. I have dived with an oxygen rebreather. Any good book or scuba diving publication that discusses rebreathers will prove that oxygen rebreathers exist. For a start, try:
  • http://archive.rubicon-foundation.org/4960
  • http://archive.rubicon-foundation.org/4958
  • http://www.bishopmuseum.org/research/treks/palautz97/rb.html
  • http://www.therebreathersite.nl/Zuurstofrebreathers/database_oxygen_rebreathersNL.htm
    • Try Google search for "oxygen rebreather" OR "oxygen rebreathers" Anthony Appleyard (talk) 14:22, 6 February 2010 (UTC)

Rebreather without nitrogen, part 2

• Anthony, I think we all agree that "oxygen rebreathers" exist, at least historically. I acknowledged this in my opening message of this thread, by mentioning a depth limit. It is my understanding that breathing pure oxygen at depth (or with any exertion) is "not good", and therefore diluting gases are used for modern scuba diving rebreathers. And as RexxS notes above, it is unclear that the diluent gas is an important component of the weight saving equation, as the weight of the tanks also figures prominently. The point is that we need a source not just to tell us that there were pure oxygen rebreathers at some point, but that the diluent weight is an important part of the overall weight saving. And even then, there is the issue of where to state this: I think the "rebreather" section is more relevant for this than "gas mixes". Crum375 (talk) 14:37, 6 February 2010 (UTC)
• Oxygen rebreathers still exist. For example the Russian IDA71 was primarily made as an oxygen rebreather with duration about 4 hours, but it has a clip-on to make it into a semi-closed-circuit nitrox rebreather. (This is distinct from many people who bought war-surplus IDA71's and adapted them into nitrox rebreathers.) Anyone who uses a rebreather will tell you that rebreathers use less cylinder contents per time than open-circuit, and even less with an oxygen rebreather. Anthony Appleyard (talk) 14:46, 6 February 2010 (UTC)
• Whether oxygen rebreathers still exist for some limited applications is not the issue. The point is that if we mention that the diluent gas is an important contributor to the weight saving when comparing rebreather to open-circuit, it needs to be properly sourced, which it isn't at the moment. Crum375 (talk) 14:50, 6 February 2010 (UTC)
• Try this version?:-

  Because compressed air is 78% nitrogen, in conventional open-circuit scuba, much of the weight of the air carried is nitrogen, and much of the oxygen inhaled is then exhaled to waste. Rebreathers do not have to carry as much nitrogen compared to the oxygen as there is in ordinary air, and most exhaled oxygen is cleaned in the absorbent canister and re-inhaled. Some shallow-water rebreathers (oxygen rebreathers) carry only oxygen. As a result rebreathers can be lighter while using the same amount of oxygen.

  Because the nitrogen in the system is kept to a minimum, decompressing with a rebreather is much less complicated than traditional open-circuit scuba systems and, as a result, divers can stay down longer. Because rebreathers produce very few bubbles, they do not disturb marine life or make a diver’s presence known; this is useful for underwater photography, and for covert work

  • We seem to be discussing two topics here. Both are well known among rebreather divers. Ask any rebreather diving instructor. See http://www.zendiving.com/divegear/rebreathers/ for a start. Anthony Appleyard (talk) 14:56, 6 February 2010 (UTC)
• (ec) I was really hoping to see a source that says rebreathers (pure oxygen or other) are lighter than comparable open-circuit gear. I can source the weight of rebreather cylinders to any shop that sells them (e.g. a Luxfer 2-litre 200 bar cylinder weighing 6 lbs (2.7 kg) for sale at http://www.divegearexpress.com/rebreathers/ccrcylinders.shtml ) and I can source the weight of open-circuit cylinders similarly (e.g. a Faber 12-litre 232 bar weighing 13 kg for sale at http://www.simplyscuba.com/products/Faber/12l232barCylinder.aspx ). But I have to use a bit of synthesis to calculate the weights of gases involved. The Luxfer 2-litre would contain 500g of oxygen (2 litres x 200 bar x 1.25 g/l); the Faber 12-litre would contain 3.5 kg of air (12 litres x 232 bar x 1.25 g/l). Is that sufficient sourcing to write something we can agree on? Perhaps something along the lines of

  Since rebreathers reuse most of the gas exhaled, they can use much smaller cylinders to store the gas. A typical open-circuit cylinder may weigh around 13 kg (30 lbs) and contain 3.5 kg (7.5 lbs) of air.<reference1> A typical rebreather cylinder might weigh around 2.7 kg (6 lbs) and contain 0.5 kg (1 lb) of oxygen or nitrox.<reference2><footnote to explain the gas calculations>

  and leave the reader to draw their own conclusions about weight? --RexxS (talk) 15:03, 6 February 2010 (UTC)

  • • I can live with that, but I think it belongs in the "rebreather" section. Crum375 (talk) 15:12, 6 February 2010 (UTC)
• "it needs to be properly sourced": the size of the cylinder(s) in a rebreather, and in air scuba with the same dive duration, is enough evidence of that. For example, the oxygen cylinder in a Siebe Gorman Salvus is tiny compared to an open-circuit air cylinder that will last for a 30 minutes dive. Anthony Appleyard (talk) 15:05, 6 February 2010 (UTC)
• Anthony, if you read WP's policies, esp. WP:V and WP:RS, you will see that "well known among diving instructors" or things that "anyone will tell you" are not counted as "reliable" or "verifiable" sources. If you'd like to add material which has been challenged, it must be reliably sourced via inline citations. For example, for your above paragraph, there must be an inline citation to a reliable source making the same points you are. In the link you provided, would you mind quoting the relevant paragraph or words which support your suggested verbiage? Crum375 (talk) 15:06, 6 February 2010 (UTC)
• Can we list the various topics that need references? The name of this section ("Rebreather without nitrogen") refers to a reference needed that oxygen rebreathers exist: that I have provided references to hereinabove. We now seem to need a reference about the saving on gas bulk usage in rebreathers: try http://www.zendiving.com/divegear/rebreathers/ ? Anthony Appleyard (talk) 15:18, 6 February 2010 (UTC)
• The Siebe Gorman Salvus's oxygen cylinder is 3.5 inches diameter and 1 foot 1.4 inches long (ignoring the cylinder neck). Anthony Appleyard (talk) 15:21, 6 February 2010 (UTC)
• Anthony, http://www.zendiving.com/divegear/rebreathers/ is just an unattributed copy of our article Rebreather as it was on 29 November 2009 (without the pictures and references). We can't use copies of wikipedia to source wikipedia. --RexxS (talk) 15:25, 6 February 2010 (UTC)
• (ec) Anthony, I think you are missing the point. I wrote the title of this section because I saw this statement: "Rebreathers do not have to carry nitrogen in addition to the oxygen, so they can be lighter while using the same amount of oxygen", and I still don't see it as correct about practical scuba diving rebreathers, not restricted to very shallow dives, and I noted the depth limit in my first sentence. The real point here is this: if you add material which has been challenged, it must be supported via inline citations by reliable sources which say effectively the same thing. So in this case, if you plan to use the source you just provided above, can you please quote from it the words or paragraph which you believe directly support your proposed material? (And I note that RexxS has pointed out that source may be invalid, so you'd need a different one in that case.) Thanks, Crum375 (talk) 15:28, 6 February 2010 (UTC)

Rebreather without nitrogen, part 3

• Try this?:-

  Because compressed air is 78% nitrogen, in conventional open-circuit scuba, much of the weight of the air carried is nitrogen, and much of the oxygen inhaled is then exhaled to waste. Rebreathers do not have to carry as much nitrogen compared to the oxygen as there is in ordinary air, and most exhaled oxygen is cleaned in the absorbent canister and re-inhaled. Some shallow-water rebreathers (oxygen rebreathers) carry only oxygen. As a result rebreathers can be lighter while using the same amount of oxygen: for example:

  A Luxfer 2-litre 200 bar rebreather cylinder weighs 6 lbs (2.7 kg) [6] and would contain 500g of oxygen (2 litres x 200 bar x 1.25 g/l).

  A Faber 12-litre 232 bar open-circuit scuba cylinder weighs 13 kg [7] and would contain 3500g of air (12 litres x 232 bar x 1.25 g/l).

  Because the nitrogen in the system is kept to a minimum, decompressing with a rebreather is much less complicated than traditional open-circuit scuba systems and, as a result, divers can stay down longer. Because rebreathers produce very few bubbles, they do not disturb marine life or make a diver’s presence known; this is useful for underwater photography, and for covert work

  Ref for longer duration :: try?:

  http://www.denninger.net/rebreather/k1-project.html

  http://www.offshoreworkersstore.com/t-rebreathers.aspx

  http://fullfatgear.com/2009/10/poseidon-rebreather/

  Anthony Appleyard (talk) 15:43, 6 February 2010 (UTC)

• As I see it, RexxS's point is that the fact that rebreathers are lighter is primarily due to the reduced weight of their tanks. The weight saving due to the actual gases carried is secondary. The material you are proposing to add seems to put focus on the diluent gases (Nitrogen in your case) and seems to imply that diluent gases is an important or primary reason for the weight saving. This seems to be incorrect, and since Wikpedia is built on reliable sources, I would like to see a high quality reliable source supporting that statement. If you don't mind, please provide a quotation (not links) from a reliable source, which you believe is making essentially the same point you are trying to make. Thanks, Crum375 (talk) 15:47, 6 February 2010 (UTC)
  • Do I need a reference to prove that 1 + 1 = 2? Smaller tanks mean less gas to be carried, and vice-versa. Anthony Appleyard (talk) 15:57, 6 February 2010 (UTC)
• From http://www.trade-schools.net/halls-diving/rebreather-deep-tech-instructor.asp (and surely THEY know their diving technology) "Rebreathers are lighter and quieter than open-circuit scuba, offering an unobtrusive approach to marine life. Rebreathers provide warm, moist air to keep you warmer while creating constant neutral buoyancy at any depth. This all provides a natural, more comfortable diving style. You will learn to use computer technology and Nitrox to quadruple your dive time underwater. As a result, it cuts your obligations for surface interval and decompression in half.". Anthony Appleyard (talk) 15:53, 6 February 2010 (UTC)
• There is no question that rebreathers are lighter. The question is why. Your quotation does not answer it. Crum375 (talk) 15:55, 6 February 2010 (UTC)
• (ec) I really don't want to appear awkward, but http://www.denninger.net/rebreather/k1-project.html points to the warning "The information on this page and that which follows is NOT complete, NOT tested, NOT approved by any agency or organization ... I cannot give you diving advice as a professional, because I am not one!". There's no way that would meet wikipedia standard of a reliable source. While http://www.offshoreworkersstore.com/t-rebreathers.aspx is another copy of the wikipedia Rebreather article. I'm sure that you can see how it would be inappropriate to use wikipedia as a source for itself. You'll find http://fullfatgear.com/2009/10/poseidon-rebreather/ is a blog and the page is written by someone called "martin". Are there any sources that we could describe as "reliable, third-party, published sources with a reputation for fact-checking and accuracy"? --RexxS (talk) 16:02, 6 February 2010 (UTC)
• OK, sorry, sorry. Anthony Appleyard (talk) 16:04, 6 February 2010 (UTC)
• Rebreathers are lighter for the same duration because open-circuit scuba throws away all the nitrogen and well over half the oxygen of each breath, and rebreathers return all exhaled gas except the carbon dioxide. Anthony Appleyard (talk) 16:04, 6 February 2010 (UTC)
• Anthony, can you provide a quotation from a reliable source which says, effectively, what you are saying? Thanks, Crum375 (talk) 16:10, 6 February 2010 (UTC)
• How about "Rebreathers are lighter for the same duration because open-circuit scuba needs much bigger cylinders" ? --RexxS (talk) 16:24, 6 February 2010 (UTC)
  • P.S. Halls are a respectable outfit and they seemed to know what they were doing when I dived with them, so I'd personally give much more credence their statements (not the one about halving the deco obligation, of course!) --RexxS (talk) 16:30, 6 February 2010 (UTC)
• From page 47, "Mixed Gas Diving" by Tom Mount and Bret Gilliam, 1993, ISBN 922769-41-9: "Fully equipped, the "Kraken" diver wears a backmounted equipment package that includes an integrated buoyancy compensator, instrumentation, decompression computer, regulator, breathing gas, etc. that weighs about 60 pounds. In the NITROX version, he has a practical operational depth of approximately 165 feet and can stay submerged well over two hours. Compare that to the multiple tanks, regulators, stage cylinders, decompression tanks or surface supplied gas, redundant BC's, etc. that the the typical high tech diver employs for deeper diving or penetrations into cave systems. It's not uncommon for the open circuit diver to wear over 200 pounds of equipment and he will still be limited to a relatively short stay underwater.". Anthony Appleyard (talk) 16:35, 6 February 2010 (UTC)
• Looks like an excellent source, Anthony. Are you going to use that to show the 140 lb weight difference is due to carrying less nitrogen? --RexxS (talk) 16:49, 6 February 2010 (UTC)
• (ec) Again, the issue is where does the rebreather weight saving (which is not in doubt) come from. According to RexxS, it comes primarily from the smaller tank weights, and only secondarily from the reduced gases being carried. If you want to make a general statement about rebreather gear weighing less, it has to be properly explained and properly sourced. Sources saying that "typically" and "it's not uncommon" for open-circuit divers to do this or that is not what we need. We need a reliable source saying "rebreather equipment is lighter than open-circuit because X Y Z." Then we can write it up in our own words. Crum375 (talk) 16:51, 6 February 2010 (UTC)
• Less gas carried means less weight and bulk of cylinders needed to carry it, and vice-versa. That should be too obvious to need a reference. Anthony Appleyard (talk) 17:09, 6 February 2010 (UTC)
• Not necessarily, in principle you can have less gas and bulkier accessories, for example. And in any case, when something is challenged, it requires a direct reliable source, since clearly (by definition) it's not obvious to the challenging editor. Crum375 (talk) 17:34, 6 February 2010 (UTC)

Rebreather without nitrogen, part 4

• The principle of rebreathers, as described in page Rebreather, shows that much less gas is used than with open-circuit scuba, and the reason. Everything follows from that. Page Rebreather has 27 references and 5 external links: that should be plenty. Anthony Appleyard (talk) 17:44, 6 February 2010 (UTC)
  • We are not discussing that page, but this one. If you have a reliable source which supports your statements, please provide a quotation which effectively says what you are saying. Thanks, Crum375 (talk) 17:54, 6 February 2010 (UTC)
• Have to agree that it needs in line citation, otherwise it's OR by synthesis. OwainDavies ^(about)_(talk) edited at 19:26, 6 February 2010 (UTC)

  Aside: A few sources and quotes to establish some basics:

  • "The nominal rate of oxygen consumption is assumed to be 1 liter/min" - Garofalo, F; Manfredi, S; Santini, S. (September 2003). "Modelling and control of oxygen partial pressure in an underwater breathing apparatus with gas recycle" (PDF). Proceedings of IEEE European Control Conference: 3.
  • "A commonly used average resting value [for rate of oxygen consumption] is 0.3 L/min" "A V'O2max of at least 3.0 L/min can usually be expected" – Camporesi, Enrico M; Bosco, Gerado (2003). "Ventilation, Gas Exchange and Exercise Under Pressure". In Brubakk, Alf O; Neuman, Tom S (eds.). Bennett and Elliott's physiology and medicine of diving (5th ed.). United States: Saunders. p. 78. ISBN 0702025712. OCLC 51607923.
  • "a respiratory minute volume for divers of around 20 l/min" - Elliott, David (March 1997). "Some limitations of semi-closed rebreathers" (PDF). SPUMS Journal. 27 (1). South Pacific Underwater Medical Society: 48.
  • "For a diver of average size and reasonable fitness, an O2max of at least 3 l/min can usually be expected and is almost universally accepted" – ibid
  • A clear exposition of the differences between O2 rebreathers, SCR, CCR, and open-circuit; from the manufacturers of Stingray and Abyss – "Rebreather FAQ". Rebreathers Australia. 7 May 2009.
    • Those sources indicate that gas consumption on open circuit averages 10-20 times the oxygen consumed in a rebreather (and the ratio increases with depth), so much less gas is carried (and the cylinders are therefore smaller). Couple that with the sizes and weights of the cylinders available for sale, and we might have something looking like reliable sources for some text. Or is that too much WP:SYN? --RexxS (talk) 20:25, 6 February 2010 (UTC)
• Yes, I think that's classical WP:SYN. We need a good secondary source which explains to us why rebreather is lighter than open-circuit. These data points are good, but we need a source for the forest, not just the trees or leaves. Crum375 (talk) 20:50, 6 February 2010 (UTC)
• I thought that the disputed paragraph was merely a short summary of some information which is in page Rebreather. Anthony Appleyard (talk) 23:21, 6 February 2010 (UTC)
  • If so, why was it not in the "rebreather" section? And if it reflects information already properly sourced elsewhere, then it should be easy for you to provide a quotation from a reliable source which effectively says the same thing we are saying. Crum375 (talk) 23:32, 6 February 2010 (UTC)
    • It is/was in Scuba diving as a brief description of a few useful salient points about rebreathers. Anthony Appleyard (talk) 23:53, 6 February 2010 (UTC)
      • In that case it should be in "rebreather", not in "gas mixes". But regardless of where it is, or how short, useful or salient it is, it must still be properly sourced, per WP:V, WP:NOR, etc. Crum375 (talk) 23:59, 6 February 2010 (UTC)
        • Do we have to fussily reference every last little bit of summary? This matter is described at greater length, and presumably referenced, in article Rebreather. Anthony Appleyard (talk) 00:09, 7 February 2010 (UTC)
          • You may be missing a point. If you are summarizing a reliable source, you cite the source and pick out the salient parts from it. But if you are summarizing another WP article (which I think is what you are saying), the fact that the material exists elsewhere on WP is irrelevant. We must provide an appropriate reliable source for any material which is challenged or likely to be challenged, per WP:V, and cite it inline in any article is it mentioned, regardless of how it's treated in other articles. Crum375 (talk) 00:17, 7 February 2010 (UTC)
• Surely the WP:SYN rule stops short of obviousness? For example, if I have a source ref that proves that x = 2, and a source ref that proves that y = 3, then surely I can assume that x + y = 5 ? Anthony Appleyard (talk) 23:27, 6 February 2010 (UTC)
  • Yes, WP:OR does allow simple arithmetic which would be obvious to any reader, but the calculations and assumptions needed here are well beyond that, and are certainly not obvious to the average man in the street. Crum375 (talk) 23:32, 6 February 2010 (UTC)
• User:RexxS wrote hereinabove: "Those sources indicate that gas consumption on open circuit averages 10-20 times the oxygen consumed in a rebreather (and the ratio increases with depth), so much less gas is carried (and the cylinders are therefore smaller). Couple that with the sizes and weights of the cylinders available for sale, and we might have something looking like reliable sources for some text. Or is that too much WP:SYN?". The only bit of logical deduction needed here is proving that people need smaller and/or fewer cylinders to contain less gas. That less bulk of contents needs less bulk of container, is obvious to anyone who has ever bought or handled liquids or gases or sand/flour/raisins/etc in containers, or who has made so much packed lunch that he finds that he needs a bigger lunchbox to put it in. For example, of course a gallon fuel-can is bigger and heavier than a pint bottle, and the well-known English proverb "You can't get a quart into a pint pot". Anthony Appleyard (talk) 10:50, 7 February 2010 (UTC)
  • Anthony, unless I am misunderstanding something, the point is that you want to state that rebreather gear is lighter than open-circuit. If this is true, and I am not doubting it, it should be possible to find some reliable source making this statement, and explaining why. Then all we'd need is to summarize that source (in the "rebreather" section where it belongs), and be done with it. If we can't find a reliable source anywhere which is saying that, it raises a question in itself. Crum375 (talk) 13:17, 7 February 2010 (UTC)

Rebreather without nitrogen, part 5

• Let us separate and list the points that User:Crum375 has raised so far, instead of casually meandering the subject from one to the other:-
• 'OXY REBR EXIST?': Ref needed that oxygen rebreathers exist. (That is why this section is called "Rebreather without nitrogen".) Seems to be settled. Anthony Appleyard (talk) 14:05, 7 February 2010 (UTC)
  • No, the issue was not whether they "exist"; they clearly do, as I alluded to in my original post by saying "over 20 feet depth". The point was that (to my knowledge) there are no rebreathers for general-purpose scuba use (over 20 or 30 feet in depth) without a diluent gas, and that point remains unless you have a reliable source showing otherwise. Crum375 (talk) 14:44, 7 February 2010 (UTC)

• 'WHY HERE?': "Why is this matter not in article Rebreather?": in a general article about scuba diving we need a short "stub-and-link" mention of rebreathers. Anthony Appleyard (talk) 14:05, 7 February 2010 (UTC)
  • No, you misunderstand. The point was that any information on why rebreathers are beneficial belongs in the "rebreather" section, not in the "gas mixes" section where it was. There is no question that rebreathers need to be described in the main scuba article. Crum375 (talk) 14:44, 7 February 2010 (UTC)

• 'LESS GAS?': Ref needed that rebreathers use less gas per dive duration: see e.g. User:RexxS's message at 20:25, 6 February 2010 (UTC) hereinabove for proof. Anthony Appleyard (talk) 14:05, 7 February 2010 (UTC)
  • No, although it would be good to have a general reference for this, I never addressed this point. Crum375 (talk) 14:44, 7 February 2010 (UTC)

• 'LESS GAS SO LESS CYL?': Ref needed that less bulk of contents need less bulk of containers. See my message at 10:50, 7 February 2010 (UTC). Anthony Appleyard (talk) 14:05, 7 February 2010 (UTC)
  • Again, I never addressed this issue, although it would be nice to have a reference. Crum375 (talk) 14:44, 7 February 2010 (UTC)

• 'REBR LIGHTER?': More generally, ref needed that rebreathers are lighter than open-circuit scuba for the same duration. See my message at 16:35, 6 February 2010 (UTC). (The amount less varies with the type and style of rebreather.) Anthony Appleyard (talk) 14:05, 7 February 2010 (UTC)
  • This was my main point, and it was referring to the unsourced paragraph which I removed, which made an argument that rebreathers are lighter because they need less (or no) Nitrogen. If there is a reliable source for this, it should be summarized and cited. Crum375 (talk) 14:44, 7 February 2010 (UTC)

• Please discuss one or more of these points, each specifically by name, or list specifically any new point that is to be brought up, so that we know where we are. Anthony Appleyard (talk) 14:05, 7 February 2010 (UTC)

I've addressed the point about where the paragraph belongs by moving it from Scuba diving#Gas mixtures, where it no longer made sense, to the section Scuba diving#Rebreather since it is part of the summary of that other article. Could we all agree that it is now in the correct section? --RexxS (talk) 16:30, 7 February 2010 (UTC)

Looks OK to me. Crum375 (talk) 17:35, 7 February 2010 (UTC)

My good wikifriend Gene Hobbs – who's the best for knowing sources that I've ever come across – tells me that the best review (secondary source) on rebreathers is this. Looking at that, I'd suggest the key points that should be summarised are:

• (1) Three types of rebreather: semi-closed circuit (SCR), fully closed circuit (CCR), and fully closed circuit oxygen rebreather;
• (2) Rebreathers recirculate the exhaled gas, removing CO2 and replacing just the O2 that was used;
• (3) CCRs offer the greatest advantages, but are most expensive;
• (4) CCRs often use as little as one-seventeenth the gas that open-circuit does and that represents a significant saving in costs for helium (if used);
• (5) CCRs minimise the amount of inert gas breathed and allow 30–40% less decompression time than open-circuit;
• (6) CCRs produce almost no bubbles;
• (7) Rebreathers require additional training beyond o/c training, and the cost of training may be significant;
• (8) Rebreathers use cylinders which may contain up to 30 cuft (840 litres) of gas;

All of those points can be sourced from Gene's reference. If we state the size and weight of an o/c cylinder (sourced to a vendor) and the same for one used in a rebreather (sourced to a vendor), then we ought to be able to say (9) that A is larger and heavier than B without requiring the reader to do more than a comparison. I think may not be violating WP:SYN by mentioning that (10) the lack of bubbles is advantageous to photography, covert operations, etc. (especially as we can source the military use to US Navy Divers Manual).

That's 10 points. Are there other important ones that ought to be included in a summary? If not, perhaps we can produce and agree a sourced text to replace the present summary section? --RexxS (talk) 23:03, 7 February 2010 (UTC)

That looks like a great ref, Rexx, thank you! And yes, I am sure we can do quite a bit with it, although it would make sense to update the main rebreather article with it too. As far as the no bubbles for photography, I am sure there are other sources for that if they don't mention it, as well as the vertical stability while breathing (not sure what the term is). I suggest you give it a first shot, and we can help as needed. Crum375 (talk) 00:32, 8 February 2010 (UTC)

Rebreather without nitrogen, part 6

I've made a draft at User:RexxS/Rebreather#Proposed draft. I'd be happy for any comments, suggestions, etc. either here or at User talk:RexxS/Rebreather. --RexxS (talk) 17:40, 12 February 2010 (UTC)

Edit Request

{{editsemiprotected}}

In the first paragraph the last line goes "According to the purpose of the dive, a diver usually moves underwater by swimfins attached to his feet, but external propulsion can come from an underwater vehicle, or a sled pulled from the surface."

I think that in the interests of gender neutrality it should read "...a diver usually moves underwater by swimfins attached to their feet..."

You bring up a good point, but I don't think the use of the singular they is appropriate in this instance, and may create the appearance of a grammatical mistake. As such, I have changed it to the gender neutral but clear "the diver's". This does create some awkwardness, but I believe it is a fair exchange. Intelligentsium 02:09, 1 March 2010 (UTC)

I've changed back to 'their' which is an acceptable singular usage, as the grammatical awkwardness of using 'the diver' twice looks far more like an error, and is more inkeeping with how other articles on WP tend to look (for this reason I suspect). OwainDavies ^(about)_(talk) edited at 07:26, 1 March 2010 (UTC)

Anthony's already solved this particular problem by using "the feet", which is gender-neutral and grammatically correct when referring to parts of the body. In general, I'd normally recommend re-writing such sentences with a plural subject: "According to the purpose of the dive, divers usually move underwater by swimfins attached to their feet, but external propulsion can come from an underwater vehicle, or a sled pulled from the surface." --RexxS (talk) 12:07, 1 March 2010 (UTC)

• "They" is plural, and has been a handy way to distinguish plural from singular, ever since the word "they" came into English (from Old Norse þeir) in Viking times; that is why English does not have the same word for "she" and "they" like in German. I see little or no reason for all this gender-neutrality pedantry; writers have used "he" to mean "that person of either sex" for centuries. Anthony Appleyard (talk) 08:17, 31 March 2010 (UTC)

Breathing underwater

"a diver uses a scuba set to breathe underwater for recreation, commercial or industrial reasons"

Personally, I breathe for the very basic reason of not dying. SCNR. 62.152.162.196 (talk) 01:36, 3 April 2010 (UTC)

Well, some of us have loftier goals than merely surviving. Crum375 (talk) 01:44, 3 April 2010 (UTC)

Reef diving skills

• The page
  • "Reef Diving Skills". Coral Reefs. 14 April 2010. Retrieved 16 April 2010.

  contains some useful information, but I can't see how the skills differ from any other buoyancy skills. In addition, per WP:ELNO #1, it "does not provide a unique resource beyond what the article would contain if it became a featured article." I'll remove the link, but leave the cite here as a resource for expanding the article. --RexxS (talk) 19:16, 16 April 2010 (UTC)

• I have put this link in. Anthony Appleyard (talk) 21:22, 16 April 2010 (UTC)
• Uhh. I tried to satisfy one side in this dispute, and it seems that I thereby automatically dissatisfied the other side in that dispute. OK, I have deleted it again. Anthony Appleyard (talk) 05:03, 17 April 2010 (UTC)
  • Anthony, I'm sorry that I didn't make myself clearer. I hope there's no dispute between 2ocean7 (talk · contribs) and me, just a difference of opinion. I noticed he'd dropped you a line on your talk page about the link, so I pointed you here, hoping you'd be able to discuss it and give a third opinion. If you think the EL meets our guidelines and is useful, I'm content to see it restored. Please don't worry about trying to satisfy my point of view, just use your best judgement. Cheers --RexxS (talk) 07:34, 17 April 2010 (UTC)

Pending changes

This article is one of a number selected for the early stage of the trial of the Wikipedia:Pending Changes system on the English language Wikipedia. All the articles listed at Wikipedia:Pending changes/Queue are being considered for level 1 pending changes protection.

The following request appears on that page:

Comments on the suitability of theis page for "Penfding changes" would be appreciated.

Please update the Queue page as appropriate.

Note that I am not involved in this project any much more than any other editor, just posting these notes since it is quite a big change, potentially

Regards, Rich Farmbrough, 23:58, 16 June 2010 (UTC).

Edit request from Whiternoise, 24 January 2011

{{edit semi-protected}} Spelling error, Inferred should be Infra-red in the table of light absorption. Whiternoise (talk) 02:48, 24 January 2011 (UTC)

Done - and thanks for spotting that. --RexxS (talk) 04:04, 24 January 2011 (UTC)

Edit request from Dlortscher, 30 January 2011

{{edit semi-protected}} In the opening section, I believe that "recreation, commercial or industrial reasons" should be changed to "recreation, commercial, industrial, scientific, or military reasons". Agree?

Dlortscher (talk) 17:57, 30 January 2011 (UTC)

No reason why scientific & military shouldn't be included. The only thing I'm now wondering is what (if any) is the distinction between 'commercial' and 'industrial' reasons? --RexxS (talk) 00:29, 31 January 2011 (UTC)

Commercial = recover treasure from shipwreck, industrial = weld a pipeline? But that's about the only "commercial" reason I can think of. Then again, what about making a movie or ad about or involving diving? Is that commercial or industrial? Franamax (talk) 04:30, 31 January 2011 (UTC)

Then there's police diving, or search and recovery diving. In the UK, professional dive instruction is "commercial" and comes under HSE regulations. Would underwater demolition be industrial or commercial (or military if performed by naval divers)? --RexxS (talk) 12:13, 31 January 2011 (UTC)

I think RexxS has just demonstrated that there is no reasonable limit to what could be written there, so the list should be omitted, leaving only "to breathe underwater." (i.e. the sentence ends at the period). Scuba diving does not depend on what people may use it for. Johnuniq (talk) 02:18, 1 February 2011 (UTC)

Partly done: based on the discussion above. -Atmoz (talk) 18:09, 3 February 2011 (UTC)

Edit request from Scubapss, 28 February 2011

{{edit semi-protected}} Scuba dive training and certification agencies Professional Scuba Schools (PSS) – based in the Italy, free diving, recreational, technical and emergency dive training and certification organization in the world

Scubapss (talk) 16:35, 28 February 2011 (UTC)

Not done: user reported to WP:UAA blocked for username and attempted spamming. Reaper Eternal (talk) 17:02, 1 March 2011 (UTC)

lead image

• Does anyone else think that the diver in the lead image on this article (File:Buzo.jpg ) looks like he's about 4 pounds overweighted? It may be an effect of the diver moving upwards when the photo was taken, but readers may not know that properly weighted and trimmed divers should not normally look like that. I scanned the image category for a photo of a properly weighted recreational diver of comparable clarity but didn't find anything. If anyone has better photo available... - BanyanTree 03:32, 6 April 2011 (UTC)
• Or perhaps he is swimming upwards at an angle. Anthony Appleyard (talk) 06:12, 6 April 2011 (UTC)
• He can't be swimming upwards with his legs bent like that. To me the diver simply looks inexperienced. Beginning divers often tilt upward and kick with bent knees - almost as though they were running underwater. His gear also looks rented (inexpensive fins, separate weight belt). While I appreciate the contribution of whomever supplied this image, it would be nice to find an image of a more experienced diver. —Preceding unsigned comment added by 68.9.183.25 (talk) 03:31, 22 April 2011 (UTC)
• I agree that the diver looks unskilled. It was my first impression on looking at the picture - poor trim, probably a kg or two negative. The quality of the kit I didnt even notice. Cheers, Peter (Southwood) ^(talk): 14:54, 5 November 2011 (UTC)

Edit request from Thoodore, 25 April 2011

In the photo caption of divers giving the "OK" sign, the word "Giving" shouldn't be capitalized.Thoodore (talk) 02:40, 25 April 2011 (UTC)

Thoodore (talk) 02:40, 25 April 2011 (UTC)

All done, thanks for that. OwainDavies ^(about)_(talk) edited at 06:23, 25 April 2011 (UTC)

Edit request from Andres.felipe.ordonez, 4 September 2011

Third line of section "Injuries due to changes in pressure": Please change: "This variation of pressure with depth will case compressible materials and gas filled spaces to tend to change volume, which can case the surrounding material or tissues to be stressed, with the risk of injury if the stress gets too high."

to: "This variation of pressure with depth will cause compressible materials and gas filled spaces to tend to change volume, which can cause the surrounding material or tissues to be stressed, with the risk of injury if the stress gets too high."

First line in last paragraph of section "Injuries due to changes in pressure": Please change: equpment to equipment

Andres.felipe.ordonez (talk) 23:09, 4 September 2011 (UTC)

Done Thanks --Jnorton7558 (talk) 01:00, 5 September 2011 (UTC)

Query on mobility

I do not understand how diver mobility is enhanced by diving bells and diving shots. Can anyone explain? Cheers, Peter (Southwood) ^(talk): 16:56, 5 November 2011 (UTC)

It's been there (Scuba diving#Being mobile underwater) since before Anthony Appleyard rejigged the page in December 2004, so I don't suppose we can ask the original author what they meant. Looked at it in comparison with the DPV assertion, I might take a guess that the intention was to say that a diver using a bell can get to an underwater location without having to swim all the down to it (= greater 'mobility'). Similarly, hauling yourself along a shotline with your arms will allow you to move faster than free-swimming. Frankly I find that too much of a stretch of the meaning of the word 'mobility' and I'd be happy to see the "Other equipment to improve mobility includes diving bells and diving shots." sentence deleted. --RexxS (talk) 17:26, 5 November 2011 (UTC)

Spring suit and steamer?

The photograph caption refers to a 'spring suit' and 'steamer'. These terms are not familiar to me , could someone define them please? Peter (Southwood) ^(talk): 20:58, 5 November 2011 (UTC)

How far from A-class?

What would be required to get this article up to A-class? Peter (Southwood) ^(talk): 21:02, 5 November 2011 (UTC)