The fin whale, a baleen whale, is closely related to the blue whale.
The fin whale, 18-27 m in length, has a distinctive colour, which has been used for identification. The right jaw is white or pale, while the left jaw is dark grey or black. The baleen plates are coloured accordingly. The whale itself is dark, but with lighter, brown-toned streaks or swirls across the back.
The powerful spout, 4-6 m, can be seen from afar in good weather conditions and the breathing cycle is between 3-5 times. The fin whale usually remains submerged for 5-8 minutes at a time, but frequently longer. The fin whale rarely lifts the fluke when diving.
The amount of fin whales in Icelandic waters has been estimated to be around 10,000 individuals during the summer months.