The organisers of the world's biggest swimming fundraising event - Swimathon 2009 - have launched an appeal for venues.

Swimming pools, leisure centres and health clubs are encouraged to register for the event at www.swimathon.org and be part of this annual event that attracts more than 500 pools across the UK.

Each year thousands of people dive in for the Swimathon challenge. Over the past two years, 30,000 swimmers have taken part in Swimathon and have raised more than £3 million for Marie Curie Cancer Care and The Swimathon Foundation.

This year, Swimathon is looking to raise more money for charity by encouraging everyone in the UK to get in the pool for the world's biggest swim and make 2009 a huge success.

Swimathon 2009 will take place on 16-19 April and provides pools with a challenge that will enthuse their customers, encourage more people to swim, help to generate positive local PR stories and enable local people to be part of a national event.

Pools can enter until 7 November and be part of the world's biggest swim by registering either online at www.swimathon.org or by calling 0845 36 700 36.