Marine engineers and naval architects design, build, and maintain ships from aircraft carriers to submarines, from sailboats to tankers. Marine engineers are primarily responsible for the internal systems of a ship, such as propulsion, electrical, refrigeration, and steering. Naval architects are primarily responsible for the ship design, including the form, structure, and stability of hulls.

Marine engineers and naval architects held about 8,300 jobs in 2014. They typically work in offices, where they have access to computer software and other tools necessary for analyzing projects and designing solutions. Sometimes, they must go to sea on ships to test or maintain the ships that they have designed or built.