Submarine propulsion system enabling underwater operation without atmospheric oxygen, typically using stored oxidizer or closed-cycle engines.

Anechoic coating: A type of sonar-absorbing material applied to submarines to reduce their acoustic signature. It consists of rubber or other materials with properties that minimize sound reflection.

Anti-ship missiles are guided missiles designed to engage and destroy naval vessels. They are typically used by aircraft, ships, or submarines to attack enemy ships.

Propulsion system combining diesel engines to generate electricity, which powers electric motors driving the vessel's propellers.

Electronic Support Measures/ELectronic INTelligence suite: a sensor system on submarines that detects, identifies, and locates radar and communication emissions for passive threat assessment and tactical advantage.

Sonar system mounted on submarine's flanks to detect targets.

Laying explosive mines underwater from a submarine.

A system of hydrophones towed behind a vessel to detect submarines and torpedoes, minimizing interference from the ship's self-noise.