Definition of "sousing"

Afore we got to the shanty Colonel Applegate stuck his head out of the door. His temper had been getting raggeder all the time, and the sousing he got when he fell overboard had just about ripped what was left of it to ravellings.

1913, Joseph C[rosby] Lincoln, chapter VIII, in Mr. Pratt’s Patients, New York, N.Y., London: D[aniel] Appleton and Company