|Men's canoe sprint|
|1948 London||C-2 10000 m|
|Canoe Sprint World Championships|
|1950 Copenhagen||C-2 1000 m|
|Men's canoe slalom|
|Canoe Slalom World Championships|
|1957 Augsburg||C-2 team|
|1951 Steyr||C-2 team|
|1959 Geneva||C-2 team|
|1953 Meran||C-2 team|
Havel won a silver medal in the C-2 10,000 m event at the 1948 Summer Olympics in London. He also won a bronze medal in the C-2 1,000 m event at the 1950 ICF Canoe Sprint World Championships in Copenhagen.
He also competed in slalom canoeing, winning seven medals at the ICF Canoe Slalom World Championships. This included a gold (C-2 team: 1957), four silvers (C-2: 1957, 1959; C-2 team: 1951, 1959) and two bronzes (C-2: 1951, C-2 team: 1953).
- ICF medalists for Olympic and World Championships – Part 1: flatwater (now sprint): 1936–2007 at WebCite (archived 2009-01-21). Additional archives: Wayback Machine.
- ICF medalists for Olympic and World Championships – Part 2: rest of flatwater (now sprint) and remaining canoeing disciplines: 1936–2007 at WebCite (archived 2009-11-09)