Thanks Bill, Jim, John, et. al. Thank you guys for weighing in. I have 2 of those thru hull fittings on my 17 and I have an aft locker so, if I have to replace those fittings, I will have to become a contortionist...after I starve myself for a month or two so I can fit in. I guess what I will probably do is keep an eye on the metal component of the thru hulls so I don't actually sink "Meg" one day. I guess I will also make some plugs that I can stuff in to the underwater side in case of failure since I'm not likely to be able to crawl back from the inside. Replacement ideas welcome. The Tube replacement idea that Bill showed me was helpful. My thru hulls are different and are from the original design I think with molded surfaces and an aluminum insert (it looks like) on the underside of the hull and the hoses on the inside are attached to what looks like a molded f/g tube, but it's so far back there I can't really tell. Anyway, thanks for the thoughts and I will keep you bay area folk updated when Meg is in the water and ready for the Angel Island Rendezvous. Michael Ray m17 383 "MEG" SF Bay