Ship of Gold in the Deep Blue Sea
It's hard to go wrong when you're starting with disaster at sea, sunken treasure, a slightly larger-than-life protagonist, and high tech exploration. Gary Kinder doesn't disappoint. SoGitDBS is a page turner. It reads like a cross between drama-at-sea journalism (e.g. The Perfect Storm, Dead Wake) and the meticulous biography-centered investigations of Tracy Kidder. It's non-fiction that reads like a novel.
There is, furthermore, a curious and surprising sequel. The book came out in 1998. Subsequent to its publication . . . stuff happened. I'm not going to spoil it. Only, after you read it--not before!--you should Google for the primary protagonist.