The War Illustrated, Volume 4, No. 92, Page i, June 6, 1941.

Photo: A Depth-Charge. A Depth-Charge has just been huried overboard from this ex-American destroyer, a German submarine being int he vicinity. The depth-charge is one of our most formidable weapons in the Atlantic battle. It can be detonated at a predetermined depth of 20, 100 or 200 feet, and can exert such pressure on the submerged vessel as to crush it. Its shock can open seams and paralyse a U-boat at a considerable distance from the scene of the explosion. Photo, Fox.