To explore the deep ocean, scientists rely on numerous pieces of high-tech equipment. This photo gallery showcases some of the remotely operated vehicles (ROVs), submersibles, and other devices that have been used. Read about the Scarlet Knight, the first underwater robotic vehicle to cross an ocean.
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Alvin, Gulf of Alaska Seamount Expedition
Credit: NOAA Office of Ocean ExplorationAlvin, a human occupied vehicle (HOV), returns to the ship after a deep ocean dive to a seamount.

ROV Recovers Volcano Monitor
Credit: David Butterfield/NOAAThe remotely operated vehicle ROPOS recovers a volcano monitor from NOAA’s New Millennium Observatory on the Juan de Fuca Ridge, off the coast of the Northwest United States. The station was set up to study geological, chemical, and biological interactions along the mid-ocean ridge system. ROPOS can now be seen in Sant Ocean Hall.

Launch of an Autonomous Benthic Explorer
Credit: Dana Yoerger/Woods Hole Oceanographic InstitutionThis autonomous operated vehicle, known as an ABE (autonomous benthic explorer), will map sites where seafloor earthquakes have occurred—enhancing our understanding of these catastrophic events.

Hybrid Vehicle Nereus
Credit: Robert Elder, Woods Hole Oceanographic InstitutionOn May 31, 2009, this one-of-a-kind hybrid robotic vehicle reached the deepest part of the ocean—the Marianas Trench, located in the western Pacific Ocean, 10,902 meters (6.8 miles) below the surface. That makes the remotely operated Nereus the deepest-diving vehicle currently in service.