Shadow Divers is an excellent book about finding sunken U-Boats in the Atlantic as well. Highly recommend.

http://www.amazon.com/Shadow-Divers-Adventure-Americans-Ever...

I'm just going to toss this here because I really enjoyed the audiobook:

Shadow Divers -
The True Adventure of Two Americans Who Risked Everything to Solve One of the Last Mysteries of World War II

https://en.wikipedia.org/wiki/Shadow_Divers

This is interesting, and I kind of know what you're getting at. I've never been a super avid reader, but ive always enjoyed fiction and most sci-fi type stuff. As i get older i find myself gravitating towards more non-fiction. I recently read "Shadow Divers" which is the true story of some divers who discover an unknown U-Boat off the coast of New Jersey and spend years and several divers' lives in the pursuit of an identification. It was completely riveting which id rarely if ever experienced in a piece of non-fiction; felt like i remember the Harry Potter books feeling when i was a teenager. So maybe try expanding the scope of your search a little.

Oh boy, you fucked up now. Here are the books I read this past year that I felt were "Good", starting from the most recent :

To Kill A Mocking Bird (Insanely good)

True Grit (Insanely good)

The Little Friend (Good)

Priceless (Very good, about art theft)

The Secret History (Insanely good)

Ready Player One (Good, nerdy)

Shadow Divers (Very good, history nerd book)

Diary of Anne Frank (Very good)

Unbroken (Very good, way better than the movie)

With The Old Breed at Peleliu and Okinawa (Very good)

Seveneves (good, but I'm a Stephenson fanboy)

The Martian (Very good, but just watch the movie).

I read a bunch of other stuff, but that's what I found really "good" this past year.

I read over 40 nonfiction books this year. Here are some favorites.

Life-changing:
Why We Sleep

Page-turner:
How to Change Your Mind

Most useful:
The Consolations of Philosophy

On startups:
Troublemakers: Silicon Valley's Coming of Age

Random but amazing:
Shadow Divers (true story about deep sea diving - think Into Thin Air)

There is a book titled Shadow Divers (I would recommend) that goes into this a bit. The book tells the story of wreck divers who find a U-boat not far from New Jersey.

The story echos your friend's concern. Wreck divers will remove anything they can from these sunken vessels; placards, insignia, gauges, etc. They will also damage the vessel in order to make room to continue exploring.

The German government was also not happy with the book's protagonists because they deem sunken vessels as graves and believe they should remain undisturbed.

Currently reading A Short History of Nearly Everything by Bill Bryson. So far, it's a really charming history of science (and well, everything else), starting from the Big Bang. Bryson has never let me down before.

I just finished Shadow Divers by Robert Kurson. That was an intense book! If you like deep sea adventure or anything U-boat, it's a worthy read.

I suggest reading the book "Shadow Divers" for a look at some of the professional diving culture. It's super interesting. This death is definitely horrible. However, reading Shadow Divers also made me think that any cave divers take on high risk every time they swim, and that this death - while tragic - is a risk this person confronted long before the incident.