Quote Originally Posted by Canuckle Head View Post
This may be a dumb question but how do you know how to match up when you go to drill from the inside? Can you see it?
A standard hole saw has a drill bit on which you attach the hole saw teeth. The drill bit is used to center your hole, it also protudes further out than the saw. The drill bit will penetrate the inside surface well before the hole is complete. You simple go to the inside of the boat and place the drill bit in the hole and start sawing.