Non-Swimmer Sets Record for Longest Unsupported Swim

Jonas Deichmann admits that he is not a serious swimmer, but he has just set the world record for the longest unsupported open water swim. Over 54 days, he swam about eight hours every day and covered 456km.  He began in Croatia and followed the Adriatic coast south, reaching Dubrovnik, near the Montenegro border, on November 22. The former unsupported record holder, Sean Conway, swam 200km in 2016.

After 59 days, Deichmann completes his swim. Photo: @jonas_deichmann


The swim was the first part of Deichmann’s global triathlon. On September 26, he cycled from Munich to Croatia, where he began swimming. He has now started the cycling leg of his triathlon across European Russia, Siberia and China.

Unlike swimming, cycling is his sport, and he has set records on the three big continental crossings: across Eurasia (Portugal to Vladivostok) in 64 days, Pan-America (Alaska to Patagonia) in 97 days and most recently, from Cape North in Norway to Cape Town in South Africa in 72 days. “I am slowly lacking challenges on the bike,” he admitted, hence the idea of this human-powered triathlon around the world.

The route. Photo: @jonas_deichmann

After the bike leg, he will sail across the Pacific to San Francisco. In case you’re wondering, he doesn’t count sailing as part of the triathlon. From San Francisco, he will run 5,040km across the U.S. to New York. Finally, he will cross the Atlantic by boat and cycle from Portugal back to his starting point, Munich.


Day 27: Camping in Trogir, Croatia after a long day swimming. Photo: @jonas_deichmann


Despite his record swim, he knew even before he began that “my swimming career will last for 460km and then it will be over.” His opinion did not change during those 54 days. “I am and will remain a cyclist.”

His main concern is now the Siberian winter. He has tested his clothes, bike and electronics in a cold chamber to confirm they should work at such temperatures but he admits that it won’t be an easy section of the route.

Day 65: Cycling through North Macedonia. Photo: @jonas_deichmann


He aims to finish the entire triathlon within 10 months and to complete every section without a support vehicle. He towed a raft with his gear while swimming, is currently bikepacking to the Pacific and will pull a trailer while running. In total, he will cover 40,000km — the distance of approximately 120 Ironmans.

To prepare, he completed a ”warm-up” across Germany last summer. In 31 days, he covered 3,600km, a mere 16 Ironman triathlons.

Rebecca is a freelance writer and science teacher based in the UK. She is a keen traveler and has been lucky enough to backpack her way around parts of Africa, South America, and Asia. With a background in marine biology, she is interested in everything to do with the oceans. Her areas of expertise include open water sports, marine wildlife and adventure travel.

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Louis-Philippe Loncke

Was he carrying food for 54 days with him in the water? No. So not unsupported. Time that young adventure Athletes learn about terminology. Longest swim not unsupported is perhaps Ben Lecomte.

Jari Cennet Tammi
2 months ago
I will bring everything from the start of my 37 day swim

Louis-Philippe Loncke

Challenge longer than the World Tri of Charlie Wittmack.

Louis-Philippe Loncke

Longest swims (unassisted or unsupported) are non-stop:
Might be also that a wetsuit is considered assisted (extra boyancy, extra warmth)

Elizabeth Rose
1 year ago

That reminds me of when I set the record in MMA being non-martial artist.