609 in 2015 and later

648 past in 2015 (updated 17-07-'15)

2Swim4Life 2015, Guildford Lido, Great Britain

Date: 
Saturday, 2 May, 2015 - 09:00 to Sunday, 3 May, 2015 - 09:00

http://www.2swim4life.com

Swim 1 mile, on the hour, every hour, for 24 hours