[Bigshrimpin]

My stringers were the same way . . . empty shells. Ocean Master has the same type of stringers and those boats are solid as a rock. If you want to add floatation - drill some holes and fill the stringers with foam or you could add 4lb pour foam floatation around the stringer system.

I got that tank from Marine Connection Liquidators for $175. It's a 52 gallon surplus tank from Maverick boats. You'll need to raise the floor 2" to use that same tank.

This picture was after a good rain and before I added the limber holes for drainage.