Hundreds of islanders are taking the plunge every day this month for the 30 Bays in 30 Days challenge.
They'll take on a sea swim at a different beach each day in July to raise money for Jersey Hospice Care and the National Trust for Jersey.
The first dip is an organised one in St Brelade's Bay at 6pm on Friday (1 July).
666 people took part in the challenge in 2021, raising more than £35,000.
The task is to swim at least 30 strokes, ideally one one in each of the 30 designated beauty spots.
There will be a group closing swim on 31 July at 4.30pm, again in St Brelade's Bay.
“It has been great to see 30 Bays in 30 Days grow in popularity over the years and become a staple part of Jersey summer. It gets everyone out an about exploring the Island, enjoying the sea and of course, raising valuable funds for two local charities.” - Marina Brockbank, Community Engagement Officer at Jersey Hospice Care.
"Please do not be put off if you think that you cannot complete the challenge in July, we encourage you to continue in August or just swim in your favourite bay as many times as you can." - Donna Le Marrec, Marketing and Events Manager at the National Trust for Jersey.
Jersey Coastguard has given tips on staying safe if you're not a regular sea swimmer:
Registration is open at 30bays30days.org.je. Swimmers can also register online throughout the month of August.

Haut du Mont trial: Island Energy 'placed health and safety at risk'
Deportation recommended after sex-demanding attacker jailed
Teenage boy arrested on suspicion of sexual touching at Millbrook Park
Eyes up! It's Air Display day...
Haut Du Mont Trial: 'It could explode', jury hears 999 calls
Haut Du Mont Trial: Worker checking gas valves spent almost 'entire' time on his phone
Red Arrows still expected for Jersey Air Show
Haut Du Mont Trial: Gas works were 'sloppy, unsafe, and cut corners', allege prosecutors