Top open water swimmers take on the Derwent River

Open water swimmers will be testing themselves over the next few weeks in the Derwent River.

The Derwent River "Big Swim" is officially recognised as one of the nation’s great swimming tests.

Run during the warmer months of the year and swum over a distance of 34 kilometres of fresh and salt water, the "Big Swim" starts in the Derwent Valley below the New Norfolk Bridge, finishing at the Tasman Bridge.

River swimmers face tough conditions with strong currents, tidal influence and temperature changes, all testing the endurance of the State, Country and World's best long-distance swimmers.

During the warmer months, keen swimmers embark on a date with the backing of an escort boat and a pilot.

With complex weather and sea conditions, there are many factors to consider, and the pilot keeps a close eye on them to identify the best "swimming window" and give entrants the greatest chance of success.

There are numerous events in which competitors can enter, which include the "Bridgewater Bridge to Bruny Island" (41 km), Lake Pedder "Big Swim" (45 km), New Norfolk Bridge to Iron Pot (60 km) & Bruny Island (58 km), to name a few.

Chris Guesdon was the first to attempt the swim, with long-distance legend Des Renford the first to complete it on January 25 1975.

Since then, 143 swimmers have completed the full course, with the fastest time by a male by Andrew Donaldson (5 hrs-35 m & 21 seconds back on March 26 2022) and the fastest female, Josie Page (5 hrs-49 mins & 37 seconds on December 5, 2025).