Combat ships are divided into surface combat ships and submarines. According to the different basic tasks, but also distinguished into different types of ships. Surface combatant ships are: aircraft carriers, battleships, cruisers, destroyers, frigates, corvettes, torpedo boats, missile boats, hunting submarines, minelayers, anti-mine ships and landing craft. There are submarines: strategic missile submarines and attack submarines. In the same type of ship, according to its displacement, different weaponry, and distinguish into different ship class, such as the United States "Nimitz" class nuclear-powered aircraft carriers, the Soviet Union's "Kara" class guided-missile cruisers and so on. In the same ship class, according to its appearance, structure and tactical and technical performance of different, but also distinguish into different types of ships. Surface combatants, standard displacement of 500 tons or more, usually called ships; 500 tons or less, usually called boats. Submarines, regardless of displacement, collectively referred to as boats. The hull line of the combatant ships are all streamlined for navigation. Surface combatant ships, according to its different principles of navigation, differentiated into displacement type, glide type, hydrofoil type and air cushion type. Submarines are usually teardrop or "cigar" type.
Service ships, also known as auxiliary ships or military auxiliary ships. Used for maritime combat support, technical support and logistical support and other services. The hull is mostly drainage type, steel structure, using diesel or steam turbine power plant. Full load displacement, small only a dozen tons, large tens of thousands of tons. Speed of 30 knots or less. Service ships are equipped with devices and equipment adapted to its purpose, some equipped with self-defense weapons, according to the use of distinction for: ① reconnaissance ship, used for maritime reconnaissance. There are electronic reconnaissance ship, marine surveillance ship. ② communication ship, used for maritime communications. There are communication relay ship, satellite communication ship, etc.. ③ Hydrographic survey ship, used for sea area and channel survey. ④ Marine survey ships are used to investigate the geology, geomorphology, hydrography, meteorology, physics, chemistry and biology of the sea. ⑤ Danger prevention and life-saving ships. (6) Engineering ship. (7) Icebreaker. ⑧ test ship, for weapons and equipment testing. There are weapons test ship and equipment test ship. ⑨ training ship, for sea training or training support. There are practice ships (boats), target ships and so on. ⑩ supply ships. Transportation ships. Repair ship, used for the repair of ships and their weapons and equipment at sea.? Hospital ship. Base service ship, used for base, harbor internal service. There are harbor transport boats, supply boats, traffic boats, harbor tugboats, beacon (buoy) boats, with cable boats, fireboats and waste oil recycling boats and so on.