Submarine is a vessel that can travel submerged under the water as well as on the water’s surface. Most submarines are naval ships. There are two main types — hunter-killer, or patrol submarines, which search for and try to sink enemy shipping, and ballistic missile submarines, which carry nuclear missiles. Naval submarines use two different types of power — conventional and nuclear. When a conventional submarine is on the surface its diesel engine makes electricity.
From a peripheral level, how submarine work can be easily understood. Here electricity is used to run the electric motors that work the propeller and also to recharge the batteries. When the submarine is submerged, the diesel engine is turned off and the electric motor is powered by the batteries. In a nuclear submarine , the power comes from a nuclear reactor. The main weapon of a hunter-killer submarine is the torpedo — a sort of underwater missile. Another type of underwater vessel is the submersible. Submersibles are small diving craft used for ocean research, exploration and the repair of undersea pipes and cables.