Masked Man

The Alvin submersible is equipped with Emergency Breathing Apparatus, or EBAs, and pilots and scientists diving in the sub are scrupulously briefed on how to use them in case of an emergency during a dive. Alvin pilot Bruce Strickrott, right, has performed hundreds of these training briefings like this one with Tan Chungyang, a graduate student at the University of Minnesota. The EBAs are the same rebreathing devices used by divers or miners in emergencies. They provide oxygen and scrub out exhaled carbon dioxide. The EBAs must seal tightly; men with beards must shave before diving. (Photo by Chris Linder, Woods Hole Oceanographic Institution)