WHOI diving safety officer Terry Rioux dons a "Mark V" diving helmet at the Mobile Diving and Salvage Unit Two, in Little Creek, Va, in June 1978. Before and during his tenure at WHOI, Rioux was a diver for the U.S. Navy and Navy Reserves. According to Rioux, the Mark V helmet—which allowed breathing gases to be pumped down from a surface ship through an umbilical to the diver—was used for heavy salvage work from before World War I up until it was replaced by a more
modern system in the 1980s.
(Photo courtesy of Woods Hole Oceanographic Institution Archives)