"Remotely operated underwater vehicle (ROV) systems equipped with underwater imaging technology can be used in conjunction with or in place of a dive team. In many cases, a system can perform an operation more quickly than a dive team. These systems--consisting of a submersible ROV, umbilical, and control console--can support both sonar and video technologies for side-by-side visual and acoustic display. Applications for ROV systems may include:  Inspecting ship hulls, pier pilings, and bridges;  Directing divers to an area of interest;  Recovering evidence that was discarded in a body of water; and,  Inspecting an object or area of interest before deploying divers."
Department of Homeland Security: https://www.dhs.gov/