What counts as a long race
A race enters this ranking if at least one of its events is at least 10 km long and is swum in one go, by one swimmer. The 10 km is not an arbitrary threshold: it is the Olympic open water distance, on the programme since the 2008 Beijing Games. Stage races, like 8 Bridges, which runs down the Hudson over seven days, and relays have a separate list: a total split over several days or several swimmers cannot be compared with a single swim.
Not all of them are races in the most common sense, with a mass start and a single date. 20 Bridges around Manhattan has eight date windows between June and October, Swim Loch Ness assigns dates by slot, and in both each swimmer has their own boat. They sit halfway between a race and a solo crossing, which we discuss in the questions further down.
At the top: the Paraná, the Amazon and the Bay of Naples
The Santa Fe–Coronda dates from 1961. The distance changes from year to year with the course, and the organiser does not state it: the Santa Fe press counted 57 km in 2025 and 59 in 2026. It is an invitation-only race, and in 2026 eighteen started: the Italian Alessio Occhipinti won for the second year running, in 8h42'59". For everyone else there is the amateur version, 48 km from the Costanera Este in Santa Fe to the Coronda bathing beach, with a 10-hour time limit, solo, in pairs or as a team.
In Peru the Travesía Amazónica runs down the Amazon for 50 km, from Tamshiyacu to Iquitos, with the current; the second edition was scheduled for 23 August 2026.
The Capri–Napoli starts from Marina Grande and finishes on the Naples seafront: 36 km, first swum on 1 August 1954. Until 1992 it awarded the long-distance world title in a single race, and from 2003 it was the final leg of the FINA world circuit for races of at least 15 km. The overall record belongs to Arianna Bridi, who in 2020 finished in 6h04'26", ahead of the men too; the men's record is Marcel Schouten's, 6h05'07", in the same edition. Giulio Travaglio has won it five times.
Lakes from end to end
In Scotland the two great lochs are swum in full. Swim Loch Ness runs from Fort Augustus to Lochend, about 36 km, with a 14-hour time limit, and the 2026 dates sold out. Loch Lomond has two races in opposite directions: the BLDSA one, 21.6 miles from Ardlui to Balloch, at night, with staggered starts and an escort boat for each swimmer, and the Swim Your Swim one, from Balloch to Ardlui, with 16 hours to finish. The first crossing of Loch Lomond was made by Gerry Forsberg, in 1959. In England the BLDSA also organises the two-way Windermere, 21 miles at night: the record is Matthew Breckon's, 8:08:44 in 2024.
On the Wörthersee, in Austria, 34 km are swum in two different races, eight days apart: the Wörthersee Swim goes out and back between Klagenfurt and Velden, the Alpen Adria goes all the way round the lake. On Lake Zurich the Marathon-Schwimmen runs from Rapperswil to Zurich over 26 km, with 12 hours to finish.
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 belong to 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.
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 Australia Manly to Bundeena crosses three Sydney bays in 36 km of ocean. There are twenty places for solo swimmers: you can only enter if you have already swum more than 20 km, and you must hold at least 3 km/h. In the Balearics UltraSwim Ibiza runs from Santa Eulària to Es Pujols, on Formentera, over 30 km, with a maximum of twenty swimmers, a 10-hour limit and three time cut-offs along the course.
In Galicia the Batalla de Rande starts from the Cíes Islands and finishes at San Simón Island, passing under the Rande Bridge, about 27 km: to get through the strait with the current in your favour you have to enter it on the rising tide. In New York the Rose Pitonof Swim runs from Manhattan to Coney Island, 27.5 km in 8 hours at most, and commemorates Rose Pitonof, who swam that course aged seventeen and in 1911 won the women's long-distance world title. In Greece the Toroneos Gulf crossing links two peninsulas of Chalkidiki over 26 km: it admits twenty swimmers, and each receives an olive wreath at the finish.