Ride Control: The PIV is outfitted with a robust computer controlled and hydraulically actuated trim tab system that works to keep the vessel, and all its passengers on a level trim. This means that even when there are great big waves on our route, the boat will be held on an even keel by 8 foot wide and six foot long metal plates that are hinged to the transom of the vessel. The shipyard that built this vessel commented to us that this is less a ferry with trim tabs as it is a set of trim tabs with a ferry. This is a stunning piece of technology that is producing massive force at high rates of speed in order to keep this 100 ton ferry on an even plane.
A little known fact about both the PIII and PIV is that much of the quiet and comfort afforded passengers on the vessels is due to fact that the entire superstructure, or cabin structure, is not rigidly connected to the hulls below! Rather, there are 100 large rubber blocks
that are bolted to the cabin on the top and to the hulls on the bottom. This removes vibration (the physical origin of sound) from traveling from the machinery spaces up into the passenger spaces. It also creates a motion dampening effect.