Yes, I know, few self respecting Rastafarians would get involved with such things, and cocaine isn't often their thing, but I could resist using the line from the William Gibson Novel.

I thought this was interesting. Something I hadn't heard much about.

http://www.time.com/time/photogallery/0,29307,2061931,00.html

Two weeks in a single-use, lowest bidder, semi-submarine. One way in and out, hot, humid, little or no safety equipment. Brave, stupid, highly motivated, likely held at gunpoint.

I'd be interested in reading about how the drug lords get the brain power to build those submarines. What do the do? Recruit (with big money) from companies that have the know-how?

Perhaps the Cocaine Industry Association might be the ones they contact for the technical help.

Partly. The hulls look like somebody who knew what they were doing designed them. The construction and interior looks like somebody with more shop smarts then book smarts rigged them up. I'd put my money on the local boat builders.