Shadow Divers is one of the best books I read in quite a while.
I started diving in 1956, when I was 17, and I qualified on Subs in 1963. So, this books catches me from two perspectives.
Robert Kurson does a masterful job of discribing both the divers involved and the lost crew of the U-Who?. Not to mention the dangers, faced and shared, by both.
You can see the darkness, normal in the Atlantic depths, and the cold that permeates your very bones. Even the terror and horror, that must have filled the sub's crew, in its' last seconds, is palpable.
If adventure, subs, diving, or the ocean, grabs your attention, this books is a "must read".
I don't suffer from ulcers, I'm a carrier.