A Narco-submarine is a drug smuggling sea vessel 

A Narco-submarine is a drug smuggling sea vessel 

A narco-submarine (also called narco-sub, drug sub and Bigfoot submarine) is a type of custom-made ocean-going self-propelled submersible vessel built by drug traffickers to smuggle drugs.[1] They are especially known to be used by Colombian drug cartel members to export cocaine from Colombia to Mexico, which is often then transported overland to the United States.[2][3]The first known vessels, detected in 1993, were semi-submersibles since they could not dive: most of the craft was submerged with little more than the cockpit and the exhaust gas pipes above the water. Newer narco-submarines are fully submersible, designed specifically to be difficult to detect visually or by radar, sonar and infrared systems.[2] Cargoes carried are typically several tons of cocaine. For example, in 2015 a cargo of over eight tons was found on a semi-submersible which had been tracked by aircraft.[4]