Fitted with Fins

On the dock, WHOI engineers (from left) Mike McCarthy, Justin Fujii, and Molly Curran attach fins to the autonomous underwater vehicle (AUV) Sentry prior to ballasting and buoyancy tests in the water. Part of the WHOI-operated National Deep Submergence Facility, Sentry can carry a wide range of scientific sampling and sensing equipment to take pictures, create detailed maps, detect chemicals, and more. It operates both in mid-water and down to 6,000 meters, including near the sea floor in a variety of terrains, so the engineers must accurately know its buoyancy for each mission. (Photo by Ken Kostel, Woods Hole Oceanographic Institution)