Appearance 
The Fin Whale is the second-largest whale in the world, after the Blue Whale. The largest Fin Whales can reach a size of over 85 feet (26 meters), a length comparable to an average Blue Whale. For this reason, Fin Whales are often mistaken for Blue Whales. They way to tell them apart is their color: Fin Whales are more gray in tone, and are more of a solid color than the mottled or speckled Blue Whales.