So on the hull side,,,you have black rtv silicone,,a flat stainless of course washer,,,and the nylock nut,,.seadoo in later years has added the "thru hull bolt",,,with the washer and nylok nut,,,your 10mm does not go in very far, often, ,people remove the intake grate to te remove a rope that is around the drive shaft,,,the bolt often strips,,,or the sleeve spins in the fibreglass,,,I actually have a nut on the back side of the rear 10 mm bolt,,,I dremel tool off the protruding nut,,,so it will not catch "lake stuff.,,the rear ones rarely strip/loosen,,,its the front ones,,,when they loosen ,,and the front of the grate drops a bit,,,well,,goodbye grate.,,NEVER...remove the intake grate,,,just remove the pump.