🏊 Clive Swims

Marathon Swimming

Marathon swimming is open water swimming's ultimate endurance test — officially any swim of 10 kilometres or more, though the classic challenges run far longer. The English Channel (~33 km), the Catalina Channel (~32 km) and the circumnavigation of Manhattan Island (~46 km) make up the famous Triple Crown of Open Water Swimming.

What it takes

• A long aerobic base — building to swims of 3–6 hours in training
• Cold water acclimatisation — many marathon swims are done without a wetsuit ("skins")
• Feeding strategy — carbs and fluids every 30–45 minutes, thrown or handed from a kayak
• Sighting and pacing — holding a steady effort for hours in changing conditions

In Sweden

Sweden has its own marathon scene — Vidösternsimmet (21 km, lake Vidöstern) is the country's classic long swim, and big lakes like Storsjön and Vättern (Vätternrundan for swimmers!) offer serious distance in cold, clear water. The brackish Baltic around Sundsvall makes for good early-season training — milder temperatures and no jellyfish worries.

Oceans Seven

Devised in 2008, the Oceans Seven is marathon swimming's ultimate bucket list — seven of the world's toughest channel swims, conceived as the aquatic answer to mountaineering's Seven Summits. Ireland's Stephen Redmond became the first person to complete all seven in 2012.

The seven swims

• North Channel — Northern Ireland ↔ Scotland (~35 km, cold and jellyfish-rich)
• Cook Strait — New Zealand's North ↔ South Island (~26 km)
• Molokaʻi Channel (Kaiwi) — Molokaʻi → Oʻahu, Hawaii (~42 km, the longest)
• English Channel — England ↔ France (~33.5 km, the classic)
• Catalina Channel — Catalina Island → Southern California (~32 km)
• Strait of Gibraltar — Spain ↔ Morocco (~14 km, the shortest)
• Tsugaru Strait — Honshu ↔ Hokkaido, Japan (~19.5 km)

All are swum under traditional channel rules — regular swimsuit, cap and goggles only, no wetsuit. Water temperatures, currents, distance and marine life make each one a different kind of challenge; finishing all seven has been achieved by only a few dozen swimmers worldwide.

Swimrun

Swimrun was invented in Sweden in 2006 with the legendary ÖTILLÖ ("island to island") race — 75 km across the Stockholm archipelago alternating between trail running and open water swimming. Teams of two stay within 10 metres of each other the whole way, swimming in their running shoes and running in their wetsuits.

The format

• Dozens of alternating swim and run legs — transitions happen in the water and on the rocks
• Swimrun wetsuit with short legs, plus pull buoy, paddles and a team tether
• Distances from ~10 km sprint events up to ÖTILLÖ's 75 km world championship

Juniskär Swimrun — our local race

Juniskär Swimrun (JSR) was Sundsvall's own swimrun race, starting and finishing at the café in beautiful Juniskär just south of the city. The course ran out among the islands, into sheltered bays and through forest terrain — one of the most scenic race settings imaginable.

Described as a small, tough and very well-organised race, JSR ran for ten editions, with the final race on 9 August 2025 — won by an Olympic gold medallist in course-record time. A beginner-friendly First 2 Try distance made it a great introduction to the sport.

→ Juniskär Swimrun on Facebook

Matfors Swimrun — the new kid on the block

With Juniskär Swimrun retired, Matfors Swimrun has stepped in — a new, smaller-scale event organised by Matfors Skidklubb in Matfors, just west of Sundsvall. The first edition ran in September and was a hit, with the club aiming to grow it into a recurring event.

• Distance: ~14.5 km total — 8 run legs (12.4 km) + 7 swim legs (2 km)
• Start/finish: Rännöbadet, Strandvägen, Matfors — at the club's home base
• Course: Rännösjön lake → the tough hills of the Uvberget ski trail → Västra Rännobodsjön → fields and forest up to the idyllic Åtjärn tarn (home to trout and char!) → back down via Lundeviken and Forsviken bays → final swim at Rännöbadet
• Entry: 200 SEK (300 SEK late entry), paid by Swish
• Mandatory gear: shoes, wetsuit, whistle, first aid kit — goggles, pull buoy, paddles and team tether optional
• Safety: boat/SUP cover at most swims; energy station at Åtjärn

→ Matfors Swimrun — matforsskidklubb.se

Around Sundsvall

The High Coast (Höga Kusten) just north of Sundsvall is perfect swimrun terrain — rocky islands, sheltered bays and forest trails all in one. Alnön and the archipelago south towards Juniskär and the Bothnian Sea offer endless island-hopping routes for training.

Upcoming Swimrun Races

Want to race? These calendars list upcoming swimrun events in Sweden, Europe and worldwide:

🗓️ ÖTILLÖ Swimrun — official World Series race calendar
🗓️ Swimrun Watch — competitive race calendar
🗓️ Swimrun Advice — European race calendar