Colombian drug traffickers are using a new secret weapon to smuggle cocaine north – drug submarines. Up to 30 meters long and nearly impossible to detect, they are capable of distributing several tons of coke in just one shipment. Dozens of subs are thought to be in operation between the coasts of Colombia and Mexico, and law enforcement estimates that another 70 will be built in the next year alone. NGC follows U.S. Drug Enforcement Agency agents and the Colombian military looking for drug subs under construction in some of the most remote jungles on the planet.