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 Open Water Swim (distance)

Longest Open Water Swim (duration)

Sarah Thomas - 168.3 km (104.6 miles) in 67 hours, 16 minutes on 7-10 August 2017. Lake Champlain, Loop around Gardiner Island (Vermont) from Rouses Point, New York. Ratified by Marathon Swimmers Federation (documentation).

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 (distance)

Longest Ocean Swim (duration)

Neil Agius - 125.7km (78.1 miles) in 52 hours, 10 minutes on 28-30 June 2021. Mediterranean Sea, Linosa (Italy) to Gozo (Malta). Swim ratified by Marathon Swimmers Federation (documentation), record under review.

Longest Lake Swim (distance)

Longest Lake Swim (duration)

Longest River Swim (distance)

Ricardo Hoffmann - 481 km (299 miles) in 84 hours, 37 minutes on 3-6 March 1981. Paraná River, Corriente to Santa Elena (Argentina).

Longest River Swim (duration)

Charles (Zimmy) Zibelman - 233km (145 miles) in 148 hours on August 1937. Hudson River, Albany to Manhattan.

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.

Longest Current-Assisted Ocean Swim (distance)

Veljko Rogošić - 194 km (120.5 miles) in 50 hours, 10 minutes on 29-31 August 2006. Adriatic Sea, Grado to Riccione (Italy).

Notes:

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.

Longest Multi-Segment Ocean Swim (distance)

Longest Multi-Segment Ocean Swim (duration)

Sarah Thomas - 132km (82.5 miles) in 54 hours, 10 minutes on 15-17 September 2019. English Channel four-way crossing, England-France-England-France-England. Ratified by Channel Swimming & Piloting Federation (documentation).

Longest Multi-Segment Lake Swim (distance)

Joe Zemaitis - 112km (69.6 miles) in 47 hours, 23 minutes on 1-3 November 2020. Roosevelt Lake, 4.5-way lengthwise. Ratified by Marathon Swimmers Federation (documentation).

Longest Multi-Segment Lake Swim (duration)

Vicki Keith - 95km (59 miles) in 56 hours, 10 minutes on 5-7 August 1987. Lake Ontario two-way crossing, Toronto (Leslie St Spit) to Port Dalhousie to Toronto (harbour). Ratified by Solo Swims of Ontario (documentation).