Rick,
The deck laps over the hull section. That joint is caulked. The main part of the rub rail (the white section not the insert)is the also caulked and is connected with about 1 1/4" stainless flat head wood screws. The screws are what keep the hull/deck connection together. If you are in the Vee Berth, carefully slide your hand behind the cabin top and the carpeted hull. You will feel the screws behind the carpet. They are spaced about 8" on center.Then the black rub rail insert covers the screws.r.w.landau