All three species are characterized by very distinctive blows or spouts. In both the bowhead and the right whales, the projection of the blow upward from two widely separated blowholes assumes a very wide V-shape with two distinct columns, which may be seen when the animals are viewed from front or back. Though this character may be visible under ideal conditions in many of the other baleen whales species as well, it is exaggerated and uniformly distinct in the bowhead and right whales and may be used as one of the primary key characters. In the sperm whale, the blow emanates from a blowhole which is displaced to the left of the head near the front and projects obliquely forward to the animal's left. This blow seen under ideal conditions positively labels a large whale as a sperm whale.

Remember, however, that wind conditions may affect the disposition and duration of the blow of any species and that a single character alone is seldom sufficient to permit positive identification.

Bowhead whale
Balaena mysticetus
p. [49]

[8] These figures are near maximum sizes recorded for the North Atlantic. All three species have been heavily exploited by whale fisheries. Therefore maximum sizes today may be significantly less than these figures (see text).

It should also be noted that differences in methods of measurements often account for discrepancies in reported lengths.

Right whale
Eubalaena glacialis
p. [52]

Sperm whale
Physeter catodon
p. [57]