It is common, I learn, for naturists to conceal their involvement from friends, neighbours and workmates for fear that they will either not understand or disapprove. So why, I ask a regular at the club, does he prefer to swim au naturel. 'When you're swimming naked, you have a real sense of freedom,' says Geoff, who has a fading all-over tan. 'We think it's unnatural to pretend your dangling bits do not exist, and hide them with swimming costumes.' Geoff's dangly bits are indeed hard to ignore as he climbs out of the water.