Open water swimming is an outdoor endurance event held in natural water environments, such as rivers, lakes, and oceans. Managed by World Aquatics (AQUA), it features prominently in the Olympic Games, World Championships, and World Cup events. Standard international competitions include men’s and women’s 3 km elimination races, 5 km and 10km events, and a mixed 4 × 1.5km relay, totaling seven events. The Olympic Games currently include only the men’s and women’s 10 km events.

At the Sanya 2026 Games, the open water swimming competition will feature the men’s and women’s 5 km races and the mixed 4×1.5 km relay. Benefiting from Sanya’s excellent natural marine environment, the competition offers ideal conditions while also featuring challenges distinct from those of indoor pools, including wind, waves, ocean currents, water quality, and local marine life. These variables challenge not only swimmers’ physical endurance but also their adaptability and overall competence.