Swimmers braved the cold to raise money for a brain and spine charity.
The swimathon, which took place in Tooting Bec Lido, invited participants to swim 21 lengths of the largest outdoor pool in the UK.
It was the first swimathon organised by charity the Brain and Spine Foundation to celebrate its 21st birthday.
Participants donned orange swimming caps with the charities logo as they took on the task.
The money raised will help support people affected by neurological conditions.
Charlotte Callin, fundraising events co-ordinator, said: "The event was fantastic, it went really well and the swimmers seemed to thoroughly enjoy it.
"Plus the rain held off till right at the end which was a complete stroke of luck after the forecast was so awful."
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