Dr. Sönke Johnsen, Dr. Alison Sweeney, Dr. Steven Haddock, and Brian Cousin participate in a blue-water dive. The divers take turns being the safety diver, who tends to the trapeze of
lines and watches out for predators, while the others look for pelagic specimens to collect. Video courtesy of Bioluminescence Team 2009, NOAA-OER.