Fundraisers at St Albans Sub Aqua Club have swum the equivalent of two marathons to raise thousands of pounds for Great Ormond Street Hospital.

The swimmers doubled their target distance of 26 miles, or one marathon, at the charity event on Saturday.

Tim Attwood, who organised the event and coaches the junior underwater hockey team at the club, described the day as a “massive success”.

He said: “It was hard work. It was tiring. It was everything you would imagine it would be.

“Each swimmer set themselves a target of 150 lengths. Some people swam 10 lengths, some did 300, and most people did it in stages.”

He added: “All in all it was brilliant. The weather was brilliant, the day was brilliant, everyone who took part was brilliant.”

Three years ago, one of Mr Attwood’s sons was cared for at Great Ormond Street Hospital, after being diagnosed with hypothyroidism when he was just one week old.

Mr Attwood organised the fundraiser as a way of saying thank you to the charity, saying: “It’s a good charity and good cause, and I really strongly believe they need all the help they can get because they do great work.”

Swimmers aged from 6 to 60 took part in the swim-a-thon, which was attended by Mayor of St Albans City and District Cllr Salih Gaygusuz.

Ali Humphrey, chairman of the underwater hockey team, said: “The most amazing part of the day was how the people who came to support us wanted to get involved and swim as well, especially the young ones.”

Money is still being raised through Mr Attwood’s Just Giving page, but so far the swim-a-thon has raised over £2,000 for the charity.

And after the success of Saturday, the Sub Aqua Club are hoping the swim-a-thon will become an annual fixture.

Ms Humphrey said: “It was a fantastic event, and I think it will be even bigger and better next year.”