The worst thing you can do to a wooden boat is take it out of the water for a lengthy time. Seriously. What happens is the planking (if not cold molded) dries and shrinks, putting stress on the fasteners. Before you can launch it, if out for a long time, you have to strip the old caulking, re-caulk, rebed the caulk with red lead putty or something newer (if ya like) and hope ya didn't caulk her too hard. If you did, the planks can break ribs or start fasteners to loosen as they swell (take up). Wood boats work and move. As seacap stated above, you usually get two rounds of refastening before ya have to do more drastic work like inserting plugs for the fasteners in the ribs or using an epoxy
filler mix in the holes. As far as sheathing goes for a boat which may need it, there are a couple of ways to go.
1. C-Flex, which Oh Joy has...
2. Impregnated Dynel using epoxy.
3. Cold molding using epoxy impregnated veneers.
4. Cold molding with veneers and a layer of Dynel between the veneer layers.
If sheathing a boat, the wood needs to be dry and in good condition. It's also advisable to refasten if possible. I would highly suggest sealing the inside of the hull with a couple of coats of epoxy but ONLY if you can get to every single
inch of it and all of the mating surfaces of framing, ribs, etc.. If you can't, leave it be so it can breathe. Otherwise, water WILL find it's way into rib
butt joints, etc. and wick into the wood. It will NOT be able to dry out later and will rot
. This will cause major (not fatal) issues and much, much work to fix.
The one thing to remember about wood boats is that EVERYTHING can be fixed or replaced, if you have the time and patience.