Thousands of swimmers are taking to the pool at Les Quennevais to raise money for charity.
Islanders of all ages are being sponsored to swim lengths, with the money raised split between nine charities promoting outdoor wellbeing.
The event has raised more than £3.8 million over the past 50 years.
More than 400 teams from businesses, schools and charities have signed to up to take the plunge.
Students from Rouge Bouillon and De La Salle schools have been among the first to get in the pool.
The chosen charities to benefit this year are Brighter Futures, Beach Ability, Jersey Mencap, Jersey Sea Cadets, Acorn Enterprises, Autism Jersey, Wet Wheels Jersey, Healing Waves and Les Amis.
Swimarathon runs from 13 to 17 March 2024.
Government gives £150k to get Jersey athletes to 2027 Island Games
Mansell Collection scales back after fall in motorbike sales
Jersey Zoo announces death of Biggy the tortoise
Jersey RFC nominated for mental health award
Jersey voted top 5 British island
Jersey food allergen law stalls despite warnings over risk to lives
Police appeal after cyclist injured in St Peter’s Valley collision
Victoria College to double bursary places
