The first aircraft to sink a submarine was a small flying boat of the Austro-Hungarian Naval Air Arm. The year was 1916 and by that time in World War I, the airplane had come to be appreciated as an important antisubmarine weapon by all combatants. With the arrival of World War II the survival of Great Britain was put in doubt by the massive destruction inflicted on the North Atlantic lifeline by German submarines. The development of anti-submarine warfare from the air was a major factor in decreasing the number of casualties to Allied merchant shipping. This book tells the story of the cat-and-mouse tactics employed by aviators and submariners to outwit each other. It also covers the development of electronic warfare and purpose-built weapons and the role they played in the lethal duel fought over World War II waters. This new edition of a book that has become a standard on the subject includes accounts of some of the most dramatic actions during both wars.