Starting at Gorey Castle, each pair had to carry everything they planned to use, so they ran in their wetsuits and swam in their running shoes.
There were two distances. The sprint distance, which had a medium to hard difficulty rating, was 19k and finished at the Farmhouse pub in St John. The full distance was 53.5k and finished at the Portelet Inn in St Brelade.
That was rated as hard, with those hoping to complete the race needing a high level of fitness.
All those taking part had to be comfortable swimming in the open sea and be able to enter from and climb out on slippery rocks.
First across the line in the overall race were Timothee Chemineau and Antonin Gelez from the Tuite River Team in a time of 7 hr 1 min 41 sec. Just four and half minutes behind them was the local pair of Mark Syvret and Wayne Quenault of team Splash N Dash.
The first women home were Rebecca Swainson and Kirsty Wood in 7 hr 34 min, followed by local triathletes Katie Silva and Melissa Messervy, who completed the course in 8 hr 28 min.
The winners of the sprint were Rhys and Gareth Jeffreys, who finished in 3 hr 2 min.