This aptly titled work takes a look at the development and operation of lighter-than-air aviation in the U.S. Navy for World War II, probably the most effective anti-submarine weapon of the war. 

Althoff, earlier the author of the impressive USS Los Angeles: The Navy's Venerable Airship and Aviation Technology , gives us a very comprehensive look at the Navy's rigid airships and blimps, including the evolution of lighter-than-air technology, the development of doctrine and tactics, and, of course operations.  The work's principal flaw is that Althoff is rather too enthusiastic about the subject, and does not clearly discuss the reasons for the abandonment of the spectacularly unsuccessful pre-war rigid airships (at the time called "flying cruisers"), which still get more print than the later very successful non-rigid blimps that are the primary focus of this work, seeking rather to suggest sinister machinations by the airplane industry rather than the inherent flaws of the technology. 

That aside, Forgotten Weapon gives the reader a very valuable look at a very overlooked aspect of the anti-submarine war and is essential for students of the subject.