 A modern variation is the wave-piercing design.The total amount of water to be displaced by a moving hull, and thus causing wave making drag, is the cross sectional area of the hull times distance the hull travels, and will not remain the same when prismatic coefficient is increased for the same lwl and same displacement and same speed.A special type of bow, called a "bulbous bow", is often used on large power vessels to reduce wave-making drag.