[QUOTE=Bull at a Gate;9798865]When I watched some gliding recently I noticed that all the single seater glider pilots wore parachutes, but none of the dual seat glider pilots did? What is the reason for that?[/QUOTE
Lazy habits, typical of Australians! In gliders, one or two seats, in the UK, nearly always parachutes are worn. If you are flying in a glider in competition you will be very happy to wear a parachute, as thermals get rather crowded. The rules as far as I remember require parachutes in competition or in cloud, but not otherwise...but the gliders are designed for the chutes to be worn.
Part of introducing beginners to gliding should be how to wear and deploy a parachute. It does concentrate the mind of the beginner!
There was a guy at a gliding club in the UK who was TOO HEAVY to safely wear a chute in a single seat glider, so he left it at the launchpoint. The NEXT PILOT was TOO LAZY to go and get it, so he flew the glider without the parachute. Unfortunately (as it was an airfield where parachuting was part of the scene) he was at about 5,000 feet, when a free-fall parachutist impacted his wing. The parachutist was instantly killed, but the glider pilot had 5,000 feet of his downward spiral to regret not bothering to get the chute.