Just finished this. It is detailed and fascinating. Interestingly, a lot of wood and concrete were used in building temporary patches to torpedo and bomb holes in the ships before pumping them out. Raising a huge ship on the bottom is as much figuring out how to get it out of the mud as it is getting it buoyant. I didn't know what a tremie pipe was until I read this book. (I'll bet a some of you know what this is.) The book discusses the dangers of the enormous amount of H2S (hydrogen sulfide) gas that builds up in a ship that's been flooded for more than month. It's very toxic and very explosive and it caused some tragedies during the time of the salvage. The author uses a lot of Naval terminology, particularly for the various "stuff" inside a warship. (It's a Naval Institute Press book.) There are more types of openings within a huge warship than you would imagine. The book is well worth the read.