Longest Open Water Swims
The Marathon Swimmers Federation (MSF) recognizes several world records for endurance in open water swimming. These records list the longest open water swims, according to both distance and duration, and sub-categorized along several dimensions:
- Surface currents: Swims that gain a net benefit from surface currents ("current assisted") vs. those with negligible or balanced currents ("current neutral").
- Route continuity: Fully continuous swims (swimmer never exits the water) vs. multi-segment routes (swimmer allowed to rest briefly on land between segments).
- Body of water: ocean swims vs. lake swims vs. river swims.
The Longest Open Water Swim
The longest continuous, unassisted-rules open-water swim, which does not gain a net benefit from surface currents.
Longest Ocean, Lake, and River Swims
The longest continuous, unassisted-rules swim in an [ocean / lake / river]. For the ocean and lake records, the swim may not gain a net benefit from surface currents.
Longest Ocean Swim - Open Currents
As described above, the overall Longest Ocean Swim record is reserved for "current neutral" swims (negligible or balanced currents). Historically, some swimmers have attempted swims in locations with strong, predictable surface currents (such as the Gulf Stream or the Adriatic coast) with the aim of maximizing their swim distance. MSF recognizes such swims in an "Open Currents" category.
- While lakes can have currents and thus some lake swims can be classified as "current assisted", we do not list a record in this category because we know of no such swim longer than the current neutral record (168km).
- Similarly, we do not recognize an "open currents" duration record. We know of no such swim longer than the current-neutral record (52h 10m).
Longest Multi-Segment Swims
The longest unassisted-rules swim along a multi-segment route in an [ocean / lake]. Minimum segment distance 25km. 10 minutes rest permitted on land between segments.