Dad's Army - Season 4 Episode 2 Don't Forget the Diver

The platoon is to participate in an exercise to place a supposed bomb in a windmill occupied by the Eastgate men. It is decided that, as the mill is by water, Frazer, in an ancient diving suit left him by a friend who died of the Dreaded Bends, will push Jones, disguised as a log, up to the mill, where Jones will discharge the 'bomb' and, thanks to clever decoy plans used to fool Square, Jones successfully makes it, only to get caught up on the windmill's sails.