Every Orca has a unique dorsal fin. Like human finger prints, no two are exactly the same and can be used in identifying individual whales. A mature male's dorsal fin can easily be as tall as a grown person. This black and white ink and pencil drawing shows a characteristic "notch" that can occur while hunting or even from swimming too close to a boat propeller. It is illegal to pursue Orcas or approach within 100 ft in motorized boats as the whales are curious about people and can be killed unintentionally. $35