More than 700 swimmers of all ages and abilities splashed down at the Magnet Leisure Centre on Saturday for the 29th annual Swimarathon.
Organised by the Lions Club of Maidenhead, the event is a popular attraction to mark the start of the year as competitors from a range of backgrounds look to raise money for charity and burn off some mince pies in the process.
This year, a total of 93 team from groups including schools, churches and clubs entered the day-long event at the centre's pool, in Holmanleaze.
It saw swimmers complete as many lengths as possible within a 55-minute time slot.
Through sponsorship, the Lions estimates £18,500 was pledged on the day, but hopes the final figure could be as high as £30,000 once all payment is received.
The group believes roughly £535,000 has been raised for a variety of good causes since the event began.
Organiser Ed Filmore said: "It just seems to be the right formula just after Christmas.
"There's a sense of community and some people do it because they want to get a few pounds of weight off.
"There's some fantastic people around Maidenhead who organise the teams.
"Without them it wouldn't happen."
Many of this year's entrants were regular participants, with 90 per cent of places for 2014 booked up within 24 hours of the 2013 Swimarathon finishing.
But 2014 also saw a first as the Mayor of Windsor and Maidenhead, Cllr Andrew Jenner, became the first incumbent mayor to take part.
Half the funds will go towards the Lions Club of Maidenhead's charitable trust, with the rest going towards the nominated charities of those taking part.
Recipients will include the Cystic Fibrosis Trust, People to Places, SportsAble, the Thames Valley Adventure Playground and a host of schools, churches and youth groups.
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