Autonomous underwater vehicles, or AUVs, are underwater robots that are used by scientists to explore the oceans without any cables connecting the AUV to a vessel. Just like land-based robots, AUVs have a variety of sensors that are used to gather information about their environment and react when faced with an obstacle.

For example, an AUV may use a forward-looking sonar to detect underwater reefs, and then to use its propulsion to glide around the reef. Underwater navigation is very critical and the robots have sophisticated navigation devices inside to keep on track and not get lost.

AUVs are some of the most advanced underwater research tools available. They can glide into waters that may be too dangerous for ships and people to enter, or they can hover over interesting seabed habitats collecting a huge variety of information. For example, an AUV can have stereo digital cameras that take rapid-fire pictures of the seabed as they glide along, which can then be mosaiced into one long image of the seafloor. Or they can be used to visit deep black smoker vents and collect oceanographic information, then return to the ship or shore by themselves.