There is a great book on the divers that went down in Pearl Harbor for ship salvage operations after the attack.
Talk about having nerves of steel.
Speaking of Pearl Harbor, there were a few Jap ‘mini-subs’ in on that attack, and those things were pretty dangerous too!
I believe they lost them all. Not sure. I know they captured at least one of them and one of their crew on a beach.
Descent Into Darkness?
Another good one is On the Bottom: The Raising of the U.S. Navy Submarine S-51
The customer reviews don't begin to describe the problems, one of which was to slip steel cables under the sub in preparation for raising by pontoons. Mind you, this is hard-hat diving (1925) and the diver had a fire hose type of water blaster to chew his way under the boat and up the other side. He had to lay on his stomach with the nozzle ahead of him and work forward through a tunnel of clay.
Half way through, the tunnel collapses behind, trapping him about 150 feet down. The guy calmly reverses the hose and placing it under his stomach and between his legs, blows the debris back out. Then he reenters the tunnel, continues on and later asks for a buoy line to be sent down so he can thread it through.
Besides nerves, the guy must have clanked when he walked.