I plan on purchasing my first performance boat here soon ,i have a question about rotten stringers and transom , when checking for both what is a good method for doing so.coin tap test ?? or are there any special methods for doing so any help would be appreciated.

I'm sure the experts will weigh in, but I think they drill a couple holes. I would not trust a coin tap personally.
Good luck!

Once you are sure you are going to spring for the bucks pay some that has a moisture meter to check it out, damn cheap insurance!

Phil

Most sellers will not allow any damage done to their boats for testing purposes. A non-invasive moisture meter would be the quickest and easiest test. This is a normal part of most surveys.
You'll probably need a survey for insurance anyway.