autonomous underwater vehicle

On May 31, the unmanned submersible Nereus became only the third craft ever to reach the full depth of the Marianas Trench, 35,770 feet below sea level. Built by the Woods Hole Oceanographic Institution, the sub is a hybrid of a remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV). The Nereus runs on its own battery power, but researchers on a mother ship send it commands over a single hair-thin fiber-optic line that’s 25 miles long but weighs just 1.35 pounds.

This month, a slow-swimming robot known as Spray will attempt to glide roughly 2,484 nautical miles across the Atlantic, from the southern tip of Greenland to the coast of Spain. An autonomous underwater vehicle, or AUV, Spray is a joint venture between the Woods Hole Oceanographic Institution in Massachusetts and the Scripps Institution of Oceanography in California. When deployed, it will act as an aquatic sentinel, gathering data on temperature, currents and salinity that will help scientists better understand the role of oceans in regulating the global climate.