Narco Subs and Low Profile Vessels Run Drugs

Semi-submersibles ('Snorkel Subs') capable of ballasting down to lower their surface profile, and controlling their running depth, but not fully submerging. These are quite rare with only a few ever captured. (Photo and description courtesy H I Sutton)

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This Japanese WWII Type A Ko-hyoteki mini-sub, captured by US forces on Guam, may be one source of inspiration for the size and even color of the Snorkel Sub at the top. Do drug lords do research?

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As with all matters submarine it was only a matter of time before Submarine Matters touched on Narco-Subs. A narco-submarine (also called narco-sub, drug sub and Bigfoot submarine) is a type of custom-made ocean-going motorised submersible or low profile vessel (LPV) built by drug traffickers to smuggle. They are especially popular with South American drug cartels to export cocaine to Mexico, then overland to the US.

The first known vessels, date to 1993, were low profile vessels (LPVs) that could not dive: most of the craft was sat low with little more than the cockpit and the exhaust gas pipes above the water. Newer narco-submarines are semi-submersible with snorkels designed specifically to be difficult to detect visually or by radar, sonar and infrared systems.

By 2008, US officials say they were spotting an average of ten per month, but only one out of ten was intercepted. Few were seized, as their crews scuttle them upon interception and they sink within a minute or so. By 2009, the US detected as many as 60 narco sub related events.

Cargoes carried are typically several tons of cocaine. They cost up to two million dollars to construct, the submarines can move enough cocaine in a single trip to make a small profit.

They are often assembled in the Columbian jungle/mangroves including heavy equipment such as propulsion gear and generators. Despite the costs, some of the craft are intended for one-time use, being abandoned at sea after a successful delivery such are the profits – but high dangers from law enforcement and other cartels.  

The design and manufacturing techniques employed in their construction have reflected skill and verve not often seen in Columbian society. The boats have become faster, more seaworthy, and of higher capacity than earlier models. An 18 m long narco-submarine can reach speeds of 18 km/h and carry up to 10 tons of cocaine. They are typically made of fiberglass, powered by a 225-260 kW diesel engine and manned by a crew of four. They have enough cargo space to carry two to ten tons of cocaine, carry large fuel tanks which give them a range of 3200 kilometers, and are equipped with satellite navigation systems. There is no toilet, and accommodation is cramped.

The complicated routes of narco-subs, surface vessels from South America to Mexico then on land to the US. See red arrows from bottom of map from Columbia to Acapulco and  Lazaro Cardenas in Mexico.

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Because much of its structure is fiberglass and it travels barely under the surface, the vessel is nearly impossible to detect via sonar or radar, and very difficult to spot visually. The newer models pipe their exhaust along the bottom to cool it before venting it, making the boat even less susceptible to infrared detection. They are most easily spotted visually from the air, though even that is difficult as they are camouflaged with blue paint and produce almost no wake. They have ballast tanks to alter the vessel's buoyancy so that they ride low in the water.

Typical Narco-Sub Specifications

Hull material: wood, fiberglass, or steel 

Length 12–24 m

Freeboard 0.5 m

No Li-ion Batteries 

Engines: single or twin diesel

Fuel capacity: 5.6 cubic metres

Range: 3,200 kilometers

Speed: 11 km/h or more

Crew: 3

Capacity 4 — 12 metric tons

Control: human or remote

On 3 July 2010 the Ecuadorian authorities seized a fully functional, completely submersible diesel electric submarine in the jungles bordering Ecuador and Colombia. It had a cylindrical fiberglass and Kevlar hull 31m long, a 3m conning tower with periscope, and air conditioning. The vessel had the capacity for about 10 tonnes of cargo, a crew of five or six people, the ability to fully submerge down to 20m, and capable of long-range underwater operation.

The most common "semi-submersible" are low profile vessels (LPVs) like the one above. A boat designed to run awash - very low to minimize radar cross-section and almost no visual silhouette. (Photo and description courtesy H I Sutton)

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In August 2005, U.S. authorities discovered an unmanned semi-submersible in the Pacific Ocean. What they discovered was a "torpedo"-style cargo container (instead of a full-featured self-propelled ship). It used a ballast tank (submersion control) to keep it at about 30m under water while being towed by a boat. This particular "torpedo" was planned to be towed by a fishing vessel. If a patrol ship is spotted, the "torpedo" cargo container is released. While still submerged, it was designed to automatically release a buoy (concealed as a wooden log so as to be mistaken for marine debris by authorities. The buoy contains a mechanism to temporarily raise and then lower its antenna and transmit its coordinates in encrypted form a few times per day.

Smugglers normally unload their cargo onto fast power boats for the final leg to shore and the semi-submersible is scuttled. None have been sighted unloading at North American ports or beaches. In 2006, a 10 metre long sub was found abandoned on the northern coast of Spain, where the authorities suspect the crew had unloaded a cargo of cocaine before fleeing. In March 2006, the Calabrian mafia ('Ndrangheta) ordered a shipment of 9 tonnes of cocaine to be transported by a narco-submarine from Colombia to Italy, but the vessel was discovered by the Colombian police while it was still under construction. More see https://en.wikipedia.org/wiki/Narco-submarine

Inside of a low profile vessels (LPV) with the engine/fuel balancing the 100+kgs drugs in the bow-cargo hold.(Diagram courtesy H I Sutton).

Legal situation

When semi-submersibles are stopped at sea, their crews usually scuttle them, sending both the boat and the cocaine to the bottom in a minute or so and leaving no evidence of trafficking. Until 2008, in accordance with maritime law, the crew was rescued and, if there was no physical evidence of wrongdoing, released without criminal charges. To address this legal loophole, the US Drug Trafficking Vessel Interdiction Act was enacted in September, 2008, making it a "felony for those who knowingly or intentionally operate or embark in a self-propelled semi-submersible (SPSS) that is without nationality and that is or has navigated in international waters, with the intent to evade detection." The penalty is a prison term of up to twenty years in the U.S.

National security issues related to torpedo style cargo containers, semi-submersible vessels, and submarines used for smuggling and/or terrorist activities were reviewed in an August 2012 article in Homeland Security Affairs. Also presented are behaviours indicating shifts in methods of operating by drug traffickers and the corresponding risk to national security.

Pete