I am swimming 2 laps of bowmoor lake near where I live on the 18th July to raise money for Prospect Hospice. That is 2.8km, far further than I have ever swum in one go before (and no pool sides to push off from either)! This 'big swim' event also happens to be the day before my 40th birthday so seemed like a good challenge before I get too ancient. For more information on the event see: http://www.prospect-hospice.net/Supporter/Fundraising-Events/big-swim