Swimmers of all ages and abilities dived in to the 32nd annual Lions Club of Maidenhead Swimarathon.
About 200 miles was covered by nearly 800 swimmers at the Magnet Leisure Centre on Saturday.
This year's event saw 98 teams, including 16 schools, take part in the swimming challenge, which involves taking turns to swim lengths of the pool for 55 minutes per team.
Mayor Sayonara Luxton came along to support the Royal Borough team, which was raising money for the Mayor’s Benevolent Fund and officially started the event with the 10am teams.
Swimmers were also surprised by Prime Minister Theresa May, who has attended the event nearly every year since she became Maidenhead’s MP.
She started the noon slot after taking selfies with and speaking to swimmers waiting for their turn.
Brenda Butler, who was Swimarathon leader for the second year, said: “People loved it, they loved seeing her she went round to talk to the swimmers and posed for pictures.”
Before leaving, the Prime Minister picked five teams from a hat to be awarded an extra £200 for their nominated charity.
The chosen teams were All Saints Junior School, Maidenhead Stroke Club, Windsor and Maidenhead Starfish Swimming Club, St Piran’s School and Cox Green Townswomen’s Guild which has taken part in the Swimarathon for 20 years.
Each team's nominated charity will receive 50 per cent of sponsorship collected with the other half going to The Lions Club's charitable trust for projects throughout the year.
This year’s nominated organisations includes the Alexander Devine Children's Hospice Service, Dorney Youth Club, Windsor Lions and Myeloma UK.
Brenda said: “There has been a few new teams and a lot of older ones returning, it has been brilliant.”
She expects a total raised at this year’s Swimarathon will hit £30,000.
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