A folding propeller is a type of propeller whose blades automatically fold out when the engine is turning, and then fold back when the engine stops. Folding propellers are found on sailing yachts, on
A feathered two-bladed Gori folding propeller.
Folding propeller of a motor glider. (The upper cowling has been removed for this photo).
Bruntons Autoprop on Irwin 44 sailing cruiser
Arplast Helice is a former French manufacturer of propellers for light aircraft and microlights. The company was based at Gargas, France. The company appears to have been wound up on 29 April 2015.
Ground-adjustable Arplast Ecoprop on ARV Super2
Arplast Ecoprop on Barber Snark