National Geographic has a slideshow that shows off major milestones in underwater photography. This image is the first color photo ever taken underwater.
Underwater color photography was born with this shot of a hogfish, photographed off the Florida Keys in the Gulf of Mexico by Dr. William Longley and National Geographic staff photographer Charles Martin in 1926. Equipped with cameras encased in waterproof housing and pounds of highly explosive magnesium flash powder for underwater illumination, the pair pioneered underwater photography.
