The Type XXIX-H submarine was an unbuilt scheme submarine designed by Germany during World War II. It was designed to replace the type VIIC submarines that were widely used at the time. The Type XXIX-H submarine was the first to introduce stealth into its design. Its sides and conning tower adopted a polyhedral design similar to that of a F-117 stealth fighter, designed to deflect the active sonar waves of enemy warships.

It is a kind of ship that can operate underwater, with concealment and strong strike capability. It is mainly used for military purposes, such as anti-ship, anti-submarine operations, intelligence gathering, mine-making and special operations. There are two main categories: regular-powered submarines and nuclear-powered submarines. regular-powered submarines use diesel engines and battery packs, while nuclear-powered submarines use nuclear reactors as power sources, with the latter having almost unlimited underwater endurance. Key features include its streamlined design to reduce underwater drag and its ability to dive to a depth of hundreds of meters. Equipped with a variety of weapons, such as torpedoes, missiles and mines, capable of striking targets at sea and on land.

The 955 strategic nuclear submarine (Russian: проекта 955 Борей, English: Project 955 Borey, NATO codename: Borei class/Dolgorukiy class, translated as the North Wind God class) is the fourth generation strategic nuclear submarine of Russia.

Torpedo, underwater weapons capable of self-navigation, guidance, attack surface or underwater targets. Carried by submarines, surface ships and aircraft, used to attack submarines, surface ships and other underwater targets. The torpedo has a wide range of uses, can automatically search for attack targets, and has the characteristics of good concealment, strong anti-interference ability, high hit rate, and high explosive power. It is one of the main attack weapons of the Navy.