"Without Remorse" one of Clancy's greatest IMO. I'm not a big fan of his books but Red October and this one were my picks. Spent too much time setting up the story for me.

As for the the "method" used by Clark, been a diver since 76. Started at 14yrs old in FL, grew up around all this stuff and all the old Vets, heard some pretty nasty tales about the chamber. Really messy stuff. Then there's the Navy.....SAT saturation divers or EDU (experimental dive unit) as they're called, slam sum suds with these old bastards and you'll hear some tales that will make your sphincter come out your mouth. Yeah, pressure has some really mean effects on the human anatomy.

Mental floss......anyone?