It extends from Knuckle Point on Karikari Peninsula in the north to Berghan Point at Hihi in the south.
There are rocky headlands, backed by many extensive beaches, such as Tokerau Beach, Taipa, Cable Bay, Coopers Beach, and Mangonui Harbour.
Doubtless Bay was named by Captain James Cook during his first voyage of Pacific exploration in 1769. When Cook sailed past the entrance to the area, he recorded in his journal "doubtless a bay", hence the name. Poor weather prevented Cook from entering the bay proper, though a number of Māori longboats put out from shore to come alongside Cook's ship Endeavour and sell fish to her crew.
Less than two weeks later, Jean-François-Marie de Surville anchored his ship the Saint Jean Baptiste in the bay. In retaliation for the theft of a longboat which had gone adrift after his ship had dragged her anchor in a storm and narrowly escaped destruction, he carried off a Māori chief and set his village on fire. While at Doubtless Bay at Christmas 1769, de Surville's chaplain Father Paul-Antoine Léonard de Villefeix OP conducted the first Christian service in New Zealand.
Whaling stations operated on the shores of the bay in the nineteenth century.
- "Doubtless Bay", An Encyclopedia of New Zealand 1966, Te Ara (retrieved 12 December 2011)
- Diana and Jeremy Pope, Mobile New Zealand Travel Guide: North Island, 7th edition revised, Reed, Wellington, 1991, p. 69.
- "Doubtless Bay Online". Doubtless Bay Promotion Inc. Retrieved 2016-03-11.
- Cook 1769, cited in Beaglehole (ed.) 1968, pp. 220-221
- John Dunmore. 'Surville, Jean François Marie de - Biography', from the Dictionary of New Zealand Biography. Te Ara - the Encyclopedia of New Zealand, updated 1-Sep-10