Tracy Tilney, of Mendip Road, Worthing, trained for seven months ahead of the challenge at Splashpoint in Worthing on Tuesday.
She said: “Worthing Samaritans is celebrating 50 years of service to the community. As a serving Samaritan of 13 years this June, I wanted to plan an event.
“I suffer from two types of arthritis and anaemia among other health issues, so have limited mobility but I love to swim.”
Tracy was feeling ‘absolutely shattered’ at the end but she said she was so glad she did it.
She added: “I couldn’t have done it without all the amazing support I’ve had and all the kind donations. It’s a wonderful charity and deserve all the support they get.”
Among supporters was Joanna Lumley, who sent Tracy a cheque for £1,000.
Tracy said: “I have received another anonyomous donation of £100. Every pound is appreciated and helps no end.”
During the swimathon, tables in the foyer were laden with literature and homemade cakes were available to help raise awareness and some much-needed funds.
Tracy has enjoyed her work with Worthing Samaritans and hopes her efforts will encourage others to become a volunteer.
She was able to talk about her role when she met Princess Alexandra during a visit to the Worthing Samaritans offices in Lennox Road on Wednesday, May 8.
Visit www.justgiving.com/fundraising/tracy-tilney to make a donation.
Samaritans is available round the clock, every single day of the year, providing a safe place for anyone struggling to cope. For more information, visit www.samaritans.org