The Royal Canadian Navy is best known for its role in the defence of convoys against attacks by U-boats, particularly those in the mid-Atlantic from 1941 to 1943. Marc Milner's 1985 book, North Atlantic Run: The Royal Canadian Navy and the Battle for the Convoys, was the first scholarly analysis of those crucial defensive operations.

The U-Boat Hunters takes up the story for the last two years of the war, when the measurement of operational effectiveness at sea shifted from success in defending convoys to the ability to hunt down and sink U-boats. The U-Boat Hunters, which completes Milner's analysis of the RCN's battle with Germany's submarines, is a pioneering study of the final years of the Atlantic war and a landmark work in both Canadian and modern naval history.