Here's something that's a good benchmark for your distance swimming. Every year Shear Magic organise a postal swim, where the aim is to swim as far as you can in 30 minutes. It's swum at your local pool and the distance swum is sent in with the entry. John will organise timekeeping for anyone wishing to do it. We've penciled it in for 18th July, so let John know if you're interested.
Regards
Tony