Messimer tells the story from both sides. German survivors who escaped from sunken U-boats explain what it was like to face the newly developed ASW weapons beneath the surface, and pilots tell what it was like from above. The author describes the German's well-organized and efficient ASW organization in the Baltic and the Helgoland Bight. He also discusses the weapons developed during the war that proved to be largely ineffective or outright failures. While his evaluations of the contributions made by aircraft and Q-ships put them in the category of only marginally effective, his analysis of the effectiveness of politics deems that ASW "weapon" the most effective of all. Solidly grounded in the best primary sources available in England, the United States, and Germany, this book is the first to address the ASW of all World War I belligerents.