The swim is a 2.4-mile (3.86 km) out-and-back ocean swim in Kailua-Kona, Hawaii that parallels the coastline. The swim course follows a single loop pattern starting approximately 100 meters from a narrow stretch of beach. Professional triathletes start 15 minutes before the amateurs.
In the out-and-back course, the triathletes swim in a clockwise direction athletes. The swim is 1.2 miles out to the turn which is a large sail boat.
Kailua Bay is home to this beautiful swim course and offers crystal clear waters with great visibility.
The race is covered by television, including cameramen who are underwater filming with scuba tanks on. The course is known for its hectic and crowded start. Many athletes who do not make the cut-off time for the swim leg complain of seasickness.
Fastest Ironman Hawaii Swim Legs In History
John Flanagan, a former world-class open water swimmer, has two of the fastest swim legs in history. Several former pool swimmers also hold some of the fastest swim splits in history. Jodi Jackson set the women's swim leg record in 1999 with a 48:43 swim.
46:41 Lars Jorgensen (USA) 1998
46:44 Lars Jorgensen (USA) 1995
46:50 Jan Sibbersen (GER) 2003
47:01 Noa Sakamoto (USA) 2008
47:02 John Flanagan III (USA) 2008
47:04 Jan Sibbersen (GER) 2004
47:15 Hiroki Hikida (JPN) 2003
47:39 Bradford Hinshaw (USA) 1986
47:41 John Weston USA 2003
47:42 John Flanagan III (USA) 2009