This parameter determines whether a drone is capable of fully functional operation below the water surface. It is not merely about water resistance, which protects the device from rain or accidental splashes, but about the ability for intentional submersion and movement in an aquatic environment. Such drones have a special design with a hermetically sealed body and motors adapted for work in water. They are often referred to as underwater drones or ROVs, short for Remotely Operated Vehicle. They are used for exploration, filming, seabed mapping, or for the inspection of underwater structures such as ship hulls or pipelines.