Collection: Drive Shaft Bellows and Boots
Bellows and boots seal the driveshaft tunnel between the engine compartment and the pump. They keep water out of the hull and keep sand and grit away from the shaft and splines.
These are rubber parts with a finite service life. They harden, crack at the flex points, and eventually split — usually somewhere you cannot see without removing the pump. A perished bellows is a common and often overlooked cause of water in the hull, particularly on skis over about ten years old that have never had one replaced.
Inspect any time the pump is off. Given the labor to access them, replacing a marginal bellows while you are already in there is the obvious call.