Strabo, Geography
H.C. Hamilton, Esq., W. Falconer, M.A., Ed.

It is probable that those who sailed in the expedition greatly exaggerated many circumstances; yet their statements prove the sufferings to which they were exposed, and that their apprehensions were greater than the real danger. That which alarmed them the most was the magnitude of the whales, which occasioned great commotion in the sea from their numbers; their blowing was attended with so great a darkness, that the sailors could not see where they stood. But when the pilots informed the sailors, who were terrified at the sight and ignorant of the cause, that they were animals which might easily be driven away by the sound of a trumpet, and by loud noises, Nearchus impelled the vessels with violence in the direction of the impediment, and at the same time frightened the animals with the sound of trumpets. The whales dived, and again rose at the prow of the vessels, so as to give the appearance of a naval combat; but they soon made off.