Tracy Arm TracyArm50.jpg 6/2/2005

The dorsal fin of a humpback whale. On humpbacks the dorsal fin is a vestigial appendage much different from the dorsal fins on killer whales. Humpbacks get their name from the curved posture they make when they dive. It's hard to appreciate the size of the humpback when this is all you can see, but they are huge creatures, sometime approaching 50 tons in size.