Ceiling
Just as a point of interest, the "walls" on a boat are actually called "ceilings" and the ceilings as we would know them are "overheads". Ok, now that class is over...

Beware of carpet. You have to know that the hull of a boat typically sweats during certain seasons, if not all year. If you glue carpet on your hull, you could be in for a nice biology experiment underneath that carpet as the moisture will soak into it and mildew. David's suggestions of attaching (via epoxy, I'm sure) wood on to the hull and then adding a nicely finished teak ceiling would be ideal since it will allow nice air flow and reduce mildew/mold.As far as removing the old...it probably won't be easy. You could get lucky but I'm betting that they used something like contact cement which is a b**** to get off. You might be able to find some nasty chemical remover, just use a good respirator & gloves.LaDonna