Well, Neal probably can add better instructions but from my experience with the Nikonos IV and V I remember that you need to remove the gasket seals every so often and lightly, and I mean very lightly coat them with silicone grease to prevent them from drying out and leaking. Also remember that just because it did not leak in the washtub, it does not mean it wont leak at higher pressure. So if you are taking it diving then better check the seals and coat them before you do.