The construction of large vessels which travel over seas, lakes, or rivers. A ship must be capable of self-sufficiency in a hostile marine environment for extended periods of time while simultaneously providing the necessities and comforts expected by passengers, the safety and timely arrival of cargo, the offensive and defensive capabilities required by warships, and a variety of other particular functions. The bulk-cargo carrier, such as an oil tanker in which the cargo is voluminous and homogeneous with no premium on speed of transport, is the most efficient mode of freight transportation.