Submarines?
Alvin, Sonar , and underwater vessels
In Washington State, all motor-propelled vessels must be equipped with An effective muffler or underwater exhaust system.
Seagoing vessels that torpedo ships are typically submarines equipped with torpedoes. These vessels operate underwater and target enemy ships by firing torpedoes, which are self-propelled projectiles designed to hit and sink their intended target. Submarines are stealthy and can launch surprise attacks on surface vessels.
Underwater vessels, such as submarines and remotely operated vehicles (ROVs), are unique due to their ability to navigate and operate in an aquatic environment, which presents challenges like pressure, buoyancy, and visibility. They are designed with specialized hulls and systems that allow them to withstand extreme underwater pressures while maintaining a stable interior atmosphere. Additionally, they often incorporate advanced technologies for navigation, communication, and data collection, enabling them to conduct research, exploration, and military operations in ways that surface vessels cannot. Their capacity to remain submerged for extended periods adds to their versatility and strategic advantage.
SOund Navigation And Ranging = SONAR Sound is used underwater to bounce off objects. The reflections back can be measured (by electronics) to find our where they are and how far away. Used by submarines, to navigate round obstacles underwater and detect other vessels.
Gills are the underwater equivalent of our lungs and they need those features in order to extract enough oxygen from the water so that they can breath.
A "navy" is the branch of a nation's armed forces principally used for naval and amphibious warfare ie. travelling and fighting on water in a fleet of surface or underwater vessels/ships.
A torpedo is a self-propelled underwater weapon with an explosive warhead. It can be launched by aircraft, ship, or submarine, against surface vessels or submarines. Torpedoes use monopropellants (e.g., Otto Fuel) as engine fuel, which has its own oxidizer, since there isn't any oxygen to sustain a combustion engine underwater otherwise.
Underwater robots work similarly to robots that run on land, however the wiring and hardware are generally kept in a different location and heavily reinforced with waterproof seals.
The common abbreviation for submarine is "sub." This term is widely used in both military and civilian contexts to refer to underwater vessels. In some contexts, "sub" can also refer to submarine sandwiches.
An underwater camera, is a camera that works underwater.
Underwater landslides, Underwater volcanic eruptions, and Underwater earthquakes