compare the length at the water line for a design with and without a bulb necessary to power the vessel at its operating speed. The higher the speed, the bigger the benefit of the bulbous bow in diminishing the necessity for a longer water line to achieve the same power requirement. Bulbs typically are v-shaped on the bottom to minimise slamming in rough seas. Sonar domes Some warships specialised for anti-submarine warfare use a specifically shaped bulb as a hydrodynamic housing for a sonar transducer, which resembles a bulbous bow but the hydrodynamic effects are only incidental. The transducer is a large cylinder or sphere composed of a phased array of acoustic transducers. The entire compartment is flooded with water and the acoustic window of the bulb is made of fiber-reinforced plastic or another material (such as rubber) transparent to underwater sounds as they are transmitted and received. The transducer bulb places the sonar equipment at the greatest possible distance from the ship's own noise-generating propulsion system. See also Axe bow #LEADGE-bow Notes References Watercraft components Fluid dynamics Nautical terminology Interference de:Bug (Schiffbau)#Wulstbug