The first time he encountered a tiger shark in the water, marine ecologist Neil Hammerschlag was in the Bahamas conducting research. His team was on a boat and hadn't seen many sharks, so when someone yelled, "Tiger shark!" he grabbed his snorkel gear and camera and jumped into the water.
"One [tiger shark] moved right in toward me and came close," Hammerschlag tells Fresh Air's Dave Davies. "It opened its mouth, and I was looking through its mouth down its gut and seeing its gills from the inside."