Is a shaft brake necessary? Does a rotating propellor offer greater drag or has it more to do with reducing wear on the stern gland etc? My main grumble is the sound created by the rotation—it's hardly loud, but it's noticable. My gearbox (engine off) doesn't prevent the shaft rotating either in forward or reverse (it's an old Hurth Syncromatic which is well over the hill and crunches when going into reverse). Maybe replacing the gearbox with another which brakes the shaftt in gear would remove the need for a shaft brake?