Take it easy, Poke. Even full displacement hulls can be so varied in their sea-worthiness that while one might roll you like crazy and the other snap your neck. Mine is a full displacement and bounces like a cork, working your legs to death.
Larry, the point was that the OP used the term "tug" without any further description. Was he talking about a real tug hull form or one of those 30 footers that will do 18 knots and the manufacturer calls it a "tug".
Without more information his question cannot be answered.