Back up. "plywood nailed to inner ribs" leaves us with a lot of possibilities. Is it lapstrake with bentwood ribs? Carvel planked? Sheet plywood nailed to built-up ribs? Is it clinch-nailed?
Next, do you own an ice pick or a very sharp awl? If you hired a marine surveyor he would show up with one of these or something close to them for probing in places where rot would set up shop. Everything depends on where and how much of the hull is damaged not on how it looks. Any boat can be salvaged if time and bank roll are not a problem. I assume you are not in that position.
Amongst wooden boat fanciers the watch-word is "a free boat is never free".
If you want better analysis go to the Woodenboat Forum. The advice there comes from those in the know. They will ask for pictures. Get those ASAP.
http://www.woodenboatvb.com/vbulletin/upload/

: Hi gang,

: I need some advice on whether to accept an offer of dubious generosity...

: Friends of mine have a neglected 14' Enterprise sailboat mouldering in their
: back yard. The build style is plywood nailed to inner ribs, presumably all
: coated with epoxy? No glass, anyway. They have offered it to me for free,
: hoping I can get her afloat again. It was built in the 1960s, improperly
: refinished a few years ago, and left to the elements. Sails and rigging
: seem good. The topsides varnish is all flaked off - no problem, easy
: sanding! But the hull is worse: flaking paint, spot delamination of the
: plywood, and apparently some substantial leakage from somewhere near the
: keel. So...

: - Can anyone offer an educated opinion on how big a project this sounds like?
: I'm not scared of sanding and painting, but the delamination and leakage
: may be endless...

: - Can anyone recommend books or web sites to help me?

: Thanks! I know this is unrelated to kayak building, but it's the kayak
: building that landed me in this situation... I sure hate to see a nice old
: boat go to waste.

: Chris
: Victoria, BC