What counts as a long race
A race is included in this ranking if at least one of its events measures 10 km or more and is swum in one go by a single swimmer. The 10 km mark is not an arbitrary threshold: it is the Olympic open water distance, featured since the 2008 Beijing Games. Stage races, such as the 8 Bridges which descends the Hudson over seven days, and relay events have a separate list: a total distance split over multiple days or among multiple swimmers cannot be compared to a single continuous swim.
Furthermore, they must be races: a start where everyone swims together, even if divided into waves, and a finish-line ranking. Crossings are excluded, where each person swims on their assigned day with their own boat, even when the route is repeated annually: the Manhattan circumnavigation of the 20 and 40 Bridges, the Swim Loch Ness, and the end-to-end Loch Lomond. Mass participation swims, where everyone starts together but no ranking is produced, are also excluded.
At the top: the Ganges, the Paraná, and the Amazon
The longest race in our calendar takes place in West Bengal. The India National Open Water Swimming Competition descends the Bhagirathi, a branch of the Ganges, from Ahiran Ghat in Jangipur to Berhampore: 81 km in a single day. Everyone starts together at 5:00 AM; in 2026, for its 80th edition, there were twenty-seven starters, with cash prizes for the top three. A 19 km race is held alongside it.
The Santa Fe–Coronda was established in 1961. The distance changes from year to year based on the course, and the organiser does not officially declare it: the Santa Fe press counted 57 km in 2025 and 59 km in 2026. It is an invitational race, and in 2026 there were eighteen starters: Italian swimmer Alessio Occhipinti won for the second consecutive time in 8h42'59". For amateurs, there is a 48 km version from the Costanera Este in Santa Fe to the Coronda balneario, which is not a race: it is swum on different dates, either solo, in pairs, or as a team.
In Peru, the Travesía Amazónica descends the Amazon River for 50 km, from Tamshiyacu to Iquitos, with the current; the second edition was scheduled for August 23, 2026.
The Capri–Napoli starts at Marina Grande and finishes on the Naples waterfront: 36 km, first swum on August 1, 1954. Until 1992, it served as the single-race world championship for long distances, and from 2003 it became the final stage of the FINA world circuit for races of at least 15 km. The absolute record is held by Arianna Bridi, who finished in 6h04'26" in 2020, ahead of the men; the men's record is held by Marcel Schouten, 6h05'07", in the same edition. Giulio Travaglio won it five times.
Lakes from end to end
On Lake Wörthersee in Austria, 34 km are swum across two different races, eight days apart: the Wörthersee Swim goes back and forth between Klagenfurt and Velden, while the Alpen Adria completes a full loop of the lake. On Lake Zurich, the Marathon-Schwimmen runs from Rapperswil to Zurich, covering 26 km with a 12-hour time limit.
In Quebec, the Traversée internationale du lac Saint-Jean has measured 32 km in a straight line from Péribonka to Roberval since 1999. The records are held by Stéphane Lecat, 6h22'48" in 2000, and Ana Marcela Cunha, 6h34'06" in 2012; Petar Stoychev won it eleven times in a row, from 2001 to 2011.
The great British lakes are swum end-to-end, but not as races. Loch Ness from Fort Augustus to Lochend (approx. 36 km), Loch Lomond between Balloch and Ardlui, and the Windermere round trip are swum on booked dates or with staggered starts, each with their own boat or kayak, and are therefore not included in the ranking. The first crossing of Loch Lomond was by Gerry Forsberg in 1959.
River marathons
On rivers, long races are almost always downstream swims. Le Flow des Gabarriers runs down the Charente for 33 km, from Châteauneuf-sur-Charente to Cognac, and presents itself as the longest non-stage marathon in France: each swimmer brings their own escort kayak, and a wetsuit is recommended. The UltraEbre covers 30,830 m of the Ebro between the jetties of Tivenys and Amposta, starting at seven in the morning, with the July water around 24 °C (75 °F). In Russia X-WATERS Volga starts from Balakhna and follows the current down to Nizhny Novgorod for 30 km, with an escort for each swimmer.
In Pittsburgh the Three Rivers Marathon Swim does the opposite: 30 km non-stop in the Ohio, the Monongahela and the Allegheny, half with the current and half against it. River races have a guide of their own: river swimming races.
Sea crossings
In the Balearic Islands, the UltraSwim Ibiza runs from Santa Eulària to Es Pujols in Formentera, covering 30 km: everyone starts together at 7:30 AM, with a maximum of twenty swimmers, a 10-hour time limit, and three time gates along the course.
In Galicia, the Batalla de Rande starts from the Cíes Islands and arrives at San Simón Island, passing under the Rande Bridge, approximately 27 km: to cross the strait with the current, one must enter with the incoming tide. In New York, the Rose Pitonof Swim goes from Manhattan to Coney Island, 27.5 km in a maximum of 8 hours, commemorating Rose Pitonof, who swam that route at seventeen and won the women's world long-distance title in 1911. In Greece, the Toroneos Gulf crossing connects two peninsulas of the Chalcidice over 26 km: it admits twenty swimmers, and each receives an olive wreath upon arrival.