A conceptual illustration of the next-generation research submersible: The WHOI-operated research submersible Alvin is a workhorse of deep sea science and exploration. Built in 1964, Alvin has made more than 4,500 dives and can reach 4,500 meters (about three miles) depth, or about 63 percent of the ocean floor. In 2004, the National Science Foundation approved a WHOI proposal to design a replacement human-occupied vehicle (RHOV) capable of diving to 6,500 meters, and has recently approved a phased approach to construction. In Phase 1, enhancements to the existing sub will include a larger personnel sphere with better electronics and viewing; better battery capacity for more on-bottom time; increased sampling capabilities; better maneuverability; and improved lighting and video systems.
(Illustration by Don Peters, Woods Hole Oceanographic Institution)