Drug Cartels' Secret Weapon

"It's a one-way vessel," Rear Adm. Nimmich told ABC News. "It's the cost of doing business for them [drug cartels]." Although drug cartels often spend a million dollars or more to build a sub, the payoffs can be enormous and justify the cost. Cartels can transport several tons of cocaine with a street value in the hundreds of millions of dollars on each sub. This image shows just how tight it can get inside the submersible. (ABC News)