Naval architecture also known as Naval engineering is an engineering discipline dealing with the design, construction, maintenance and operation of marine vessels and structures. Naval architecture involves basic and applied research, design, development, design evaluation and calculations during all stages of the life of a marine vehicle. Preliminary design of the vessel, its detailed design, construction, trials, operation and maintenance, launching and dry-docking are the main activities involved. Ship design calculations are also required for ships being modified (by means of conversion, rebuilding, modernization, or repair). Naval architecture also involves formulation of safety regulations and damage control rules and the approval and certification of ship designs to meet statutory and non-statutory requirements.

Marine engineering broadly refers to the engineering of boats, ships, oil rigs and any other marine vessel or structure. Specifically, marine engineering is the discipline of applying engineering sciences, mostly mechanical and electrical engineering, to the development, design, operation and maintenance of watercraft propulsion and on-board systems; e.g. power and propulsion plants, machinery, piping, automation and control systems etc. for marine vehicles of any kind like surface ships, submarines etc. Marine engineers and naval architects are similar professions.