Ship In A Storm

Most commercial vessels have full hull-forms to maximize cargo capacity. Hulls are usually made of steel, although aluminum can be used on faster craft, and fiberglass on the smallest service vessels. Commercial vessels generally have a crew headed by a captain, with deck officers and marine engineers on larger vessels. Special-purpose vessels often have specialized crew if necessary, for example scientists aboard research vessels.
Commercial vessels are typically powered by a single propeller driven by a diesel or, less usually, gas turbine engine. The fastest vessels may use pump-jet engines.
• Naval vessels
Naval vessels are those used by a navy for military purposes. There have been many types of naval vessel. Modern naval vessels can be broken down into three categories: surface warships, submarines, and support and auxiliary vessels.