One of the most common dinghy hulls in the world is the Laser hull. Usually, they have steel hulls and a steel superstructure. Kauri is a superb timber for building the hulls and decks of boats. Semi round bilge hulls are somewhat less round. The ships were also armed with submerged torpedo tubes in their hulls. In lightweight antisubmarine torpedoes designed to penetrate submarine hulls, a shaped charge can be used. Many marine organisms have the capacity to attach themselves to vessel hulls. There are multiple advantages to using composite materials in ship hulls. The effect of explosive shells lodging into wooden hulls and then detonating was potentially devastating. The submerged hulls are minimally affected by waves. The ships had iron plating added to their hulls. In the 1870s schooner hulls were converted to screw tugs. It has been used for the vertical fin on seaplane hulls and floats. Dehulling is the process of removing the hulls (or chaff) from beans and other seeds. These rigs drill through holes in the drillship hulls, known as moon pools.