Submarine is a kind of ship that can walk underwater. The earliest submarine appeared before the first World War. It was widely used at the beginning of the first World War. With the explosive development of modern science, submarines have changed from the earliest manual drive to diesel electric power, and then to the present nuclear power. At present, the major military powers in the world have the underwater combat power of nuclear submarines and conventional submarines.

As far as the current world is concerned, there are many strategic weapons and equipment necessary for powerful countries. Nuclear submarines are one of them. To some extent, the strategic significance of nuclear submarines has surpassed that of aircraft carriers. Nuclear submarines are not only a symbol of a country's strong navy, but also a symbol of a country's strength, and their strategic significance is extraordinary.

Source: @nick3xl