Although most people now think of swimming as the indoor pool programme, competitive swimming has its roots very much in taking to the water outside.
Marathon swimming rose to significance after the International Olympic Committee listed a 10km race as one of the events for the 2008 Beijing Olympic Games.
Marathon races can take place in any large outdoor body of water: seas, lakes, rivers, canals, reservoirs. The distance of each event varies from 1km to 80km, but at major competitive level, the typical distances are 5km, 10km and 25km.
Swimming in outside has a long and colourful history dating back as far as 36BC, when the Japanese organised the first outdoor swimming races. The Romans held high-profile races in the Tiber, when thousands would crowd along the banks to watch and cheer. The Knights in the middle ages reputedly had to swim in full armour as one of their seven required agilities.
Although marathon races had been held for over a hundred years it was not until 1986 that FINA, swimming’s world governing body, officially recognised the event again and added it to the international competition calendar
The first ever Olympic 10km marathon swimming race was included in Beijing 2008. Team GB clinched three medals in this event – half the medals on offer - with David Davies winning silver in the men's event, and Keri-anne Payne (silver) and Cassandra Patten (bronze) both making the women's podium.
Payne has continued to compete at the top level since Beijing, winning the World Aquatics Championship title in both 2009 and 2011 then finishing fifth at the London 2012 Olympics in a thrilling race on the Serpentine, Hyde Park.
In men's marathon swimming, Jack Burnell became the first athlete to secure a named quota place for the Rio 2016 Olympics with his performance at the World Championships in Kazan.
Interestingly, world marathon swimming records are not kept by FINA simply because outdoor venues can be so different. This is not just in length but differences such as water conditions, water temperature and weather conditions.
Marathon Swimming Calendar
Check out the full calendar of events, competitions and camps that our marathon swimming athletes will attend throughout 2016.