hi, the mac 25 i have just purchased has 2 holes in the bottom of the hull. one midships aft, and the other one stbd both below the water line. when i purchased the boat these holes were attached to 2 sinks, one in the head and the other aft by the keel winch. what were they originally used for? next question: the fiberglass seats in the cabin port side and under the bow seemto be abnormally flexible when i sit on them without the pads, the fiberglass pushes down. i think its because the foam is not all in place. could this be a problem and is it important to replace the foam for support?Any help will be greatly appreciated, thanks.