Around 700 swimmers braved the icy waters to take part in Tenby's Boxing Day Swim in Pembrokeshire.
Ranked as one of the country's top festive events, the swim on North Beach is now in its 46th year - but its family origins date back 100 years.
It is organised by the Tenby Sea Swim Association (TSSA) and has raised over £250,000 for charities.
This year's fancy dress theme was The Music of the Sea.
Speaking on BBC Radio 2, TSSA chairman Chris Osborne said the swim was a "fantastic way of breaking out of the indulgencies of Christmas Day".
"As soon as you come out from the sea you're suddenly awake again and ready for action."
Mr Osborne said participants did not have to swim, they just have to "immerse themselves".
"The theory is you charge in, and if there's six or seven hundred people charging with you, you haven't got much of a choice."
Mr Osborne predicted the sea temperature would be around five or six degrees.
The event follows the 52nd Porthcawl Christmas morning swim which was held yesterday.