Marine engineering is a specialized field of study which deals with the engineering aspects of marine related equipment found on board ships, boats and so forth. In fact it is a very vast subject and there are several related fields of study such as naval architecture which may not directly fall under the purview of marine engineering but act as sister arenas.
Marine vessels come in various shapes and sizes and mainly we will mainly study about commercial vessels although naval vessels are not much different at least as far their engineering aspects are concerned, though they do have substantial differences in terms of their purpose and operations.
Specifically, marine engineering is the discipline of applying engineering sciences, including mechanical engineering, electrical engineering, electronic engineering, and computer science, to the development, design, operation and maintenance of watercraft propulsion and on-board systems and oceanographic technology. It includes but is not limited to power and propulsion plants, machinery, piping, automation and control systems for marine vehicles of any kind, such as surface ships and submarines.
Naval architects are concerned with the overall design of the ship and its propulsion through the water.
Mechanical engineers design the main propulsion plant, the powering and mechanization aspects of the ship functions such as steering, anchoring, cargo handling, heating, ventilation, air conditioning interior and exterior communication, and other related requirements. Electrical power generation and electrical power distribution systems are typically designed by their suppliers; only installation is the design responsibility of the marine engineer.
Oceanographic engineering is concerned with mechanical, electrical, and electronic, and computing technology deployed to support oceanography, and also falls under the umbrella of marine engineering, especially in Britain, where it is covered by the same professional organisation, the IMarEST.
Civil engineering for an offshore environment, the design and construction of fixed and floating marine structures, such as oil platforms and offshore wind farms is generally called offshore engineering.