Recognising a cetacean from its blow

Offshore, you often see a cetacean’s blow before the animal itself. Its shape, its height and its angle often give away the species: the 12 m vertical column of the blue whale, the V-shaped double jet of the right whale, or the sperm whale’s distinctive oblique blow, angled forward and to the left.

The widget above brings together seven blow profiles to train your eye for identifying cetaceans at a distance, a valuable reflex on an observation trip.

The blow, the first clue to identification at sea

The blow is not water but exhaled air: the abrupt decompression and the humidity produce a visible condensation, sometimes mixed with mucus. Its height and shape depend on the anatomy of the blowholes (a single one in odontocetes, two in mysticetes) and on the force of the exhalation.

In practice, the blow is read together with other clues: the dorsal fin, the dive sequence and whether or not the tail (fluke) is raised before sounding. Since wind and distance can distort it, it is always combined with the overall silhouette to confirm the species.

Going further: follow our guide How to identify a cetacean, practise with the quiz Identify my cetacean and compare the morphometrics of the species.