A bench mounting apparatus to determine the stability of a pontoon with its centre of gravity metacentric height and metacentre at various heights. This experiment allows students to determine the stability of a pontoon with its centre of gravity at various heights. Determination and analysis of the stability of floating bodies, such as ships, rafts and pontoons, is important throughout many branches of engineering. They can then compare this to predictions calculated from theory. The experiment consists of a rectangular pontoon floating in water. The pontoon has a plastic sail with fi ve rows of slots. The slots are equally spaced around the centre line. These rows are at equally spaced heights on the sail.