They are called different things, but heats and waves are specific group of individuals who start at the same time in an open water swimming competition.
Individuals in specific waves can be determined by gender, age, speed, ability or distance or course to be swum. Waves are usually started in different intervals that can generally range from 1-10 minutes. At very large races, racers may be finishing the entire race when the last wave begins their swim or even on different days.
Photo shows a heat of swimmers at the Midmar Mile in South Africa before the start. Some of these swimmer wear a golden cap which identifies them as members of the 8 Mile Charity Club.
Southern California native, born 1962, is the creator of the WOWSA Awards, Oceans Seven, Openwaterpedia, Citrus Corps, World Open Water Swimming Association, Daily News of Open Water Swimming, Global Open Water Swimming Conference. He is Chief Executive Officer of KAATSU Global and KAATSU Research Institute. Inductee in the International Marathon Swimming Hall of Fame (Honor Swimmer, Class of 2001) and Ice Swimming Hall of Fame (Honor Contributor - Media, Class of 2019), recipient of the International Swimming Hall of Fame's Poseidon Award (2016), International Swimming Hall of Fame's Irving Davids-Captain Roger Wheeler Memorial Award (2010), USA Swimming's Glen S. Hummer Award (2007, 2010) and Harvard University's John B. Imrie Award (1984). Served on the FINA Technical Open Water Swimming Committee and as Technical Delegate with the 2011 Special Olympics World Summer Games, and 9-time USA Swimming coaching staff. Note: WOWSA only recommends products or services used or recommended by the community. WOWSA does not receive compensation for links or products mentioned on this site or in blog posts. If it does, it will be indicated clearly on that specific post. See WOWSA's privacy policy for more information.