The United States Navy fleet submarine USS Tang (SS-306), underway in Mare Island Sound during her shakedown trials (US Navy photo)

My first book about WW2 was a book about US submarine warfare in the Pacific. Ever since, I've been particularly interested in submarine warfare. And I've accumulated at least as many books about submarine warfare as I have about any other single aspect of WW2. As with my books about land and sea combat, almost all my books about sub warfare divide neatly into three groups: general books about the whole topic, books about the European war, and books about the Pacific war.