Scuba Diver, McMurdo Sound, Antarctica, 1986
Photograph by Bill Curtsinger
A crack in the ice shelf, called a lead, gives a diver access to (and escape from) the frigid waters of Antarctica's McMurdo Sound. Those who brave the water temperatures of 28 degrees Fahrenheit (minus 2.2 degrees Celsius) here are rewarded with unsurpassed visibility and unique sea life that has developed in isolation for some 40 million years.
