Narco-Submarines Guide: The Underwater World of Drug Trafficking


    1.0 Introduction

    A Narco Submarine, also known as a drug submarine or smuggling submersible, is a type of watercraft used by drug traffickers to transport illegal substances, most commonly cocaine. They are mainly used to move drugs from South American countries such as Colombia to North America, especially Mexico and the United States. In recent years, there has been an increase in the use of these vessels to traffic narcotics into Europe and especially Spain.

    These submarines are built to avoid law enforcement patrols. Law enforcement agencies such as the US Coast Guard, devote considerable resources to the detection and interdiction of narco-submarines, as they pose a significant challenge to drug interdiction efforts. Despite these efforts, narco-submarines continue to be used by drug traffickers due to their ability to covertly transport large quantities of narcotics.

    In this article, we explore the history of these vessels and the different types that exist today. It also looks at their limitations and operations where they have been most relevantly used. This article focuses on the use of narco submarines in America and its expansion to Europe through Spain.

    2.0 History

    2.1 Origins

    In the 1980s, smugglers favoured the use of light aircraft and go-fast boats to move illicit substances. These go-fast boats were powerboats with extra outboard engines that made it easier to evade authorities. However, as radar technology advanced, go-fast boats became increasingly susceptible to radar detection, prompting the creation of semi-submersible vessels (source).

    The first encounter with a semi-submersible occurred in 1988, when US authorities discovered an unmanned 6.4 m (21 ft) submarine in Boca Raton, Florida. It was made to be remotely controlled and towed by a boat. Since the hatch could only be opened from the outside, investigators and authorities suspect the sub was used for smuggling even though it was empty at the time of its seizure (source).

    2.2 Cartel de Medellín

    In the early 1990s, the Medellin Cartel of Colombia started to view “narco-subs” as a sneaky and cutting-edge technique of product distribution.  The Colombian drug cartels at the time understood the economic value of vertical integration, meaning that they controlled the different steps in the product value chain (e.g. coca cultivation, manufacturing, distribution, etc.) to maximise profits.  Narco-subs controlled the delivery of narcotics to their destination while reducing the risk of detection, interception, and apprehension.  

    As go-fast boats became more of a liability, The development of a craft that could go great distances, avoid radar, and be self-propelled seemed to be the main objective of drug traffickers. Colombian drug cartels started investing in narco-submarines as an alternative way of distribution.  The cartels hired engineers from the Russian Navy to design and build narco-submarines.  

    The remaining lieutenants and their different growing drug trafficking organisations continued to invest in narco-submarine technologies after the early 1990s fall of the Medellin Cartel and the following arrests of the Cali Cartel leaders.

    Coast Guardsman jumps onto narco-submarine loaded with drugs in Pacific Ocean I. Video: ABC7.

    2.3 The spread of Narco-submarines

    As already mentioned, in 1988, authorities discovered an unmanned 6.4 m (21 ft) submarine near Boca Raton, Florida. It was intended to be pulled by a boat and submerged remotely. The submarine was empty, but officials and authorities suspect it was used for smuggling after it was discovered that the hatch could only be opened from the outside (source).

    However, the first ‘narco-submarine’ was discovered in 1993 close to Colombia’s San Andres Islands. It wasn’t a fully underwater craft, though. The San Andres Narco-Sub was a semi-submersible (SPSS) that could not go all the way under the water.  The cockpit and exhaust tubes stayed above water while most of the surface craft slid underwater. It was around 7 metres long, could carry up to 2 tonnes of cargo, and had a crew of 2. The manufacturers of the watercraft primarily used wood and fibreglass. 

    Narco-sub technology and the means to detect them have advanced throughout the years. Authorities in Colombia and the United States were able to discover, intercept, and capture drug-carrying vessels with greater ease thanks to advancements in detection and monitoring technologies. For instance, in 2007, the U.S. Coast Guard adjusted their underwater acoustic sensors to listen for submarines. In response, drug traffickers developed increasingly sophisticated vessels with features like electronics such as depth sonar and long-range HF-SSB radio communications capabilities, navigation systems, anti-radar features, and water-cooled mufflers. All these make detection more challenging. 

    Fibreglass submersible built and used by Colombian drug smugglers.

    2.4 Low-Profile Vessels

    Since 2006, law enforcement has captured low-profile vessels or LPVs. These vessels were primarily made from more advanced materials like fibreglass. Early LPVs looked like sealed ‘go-faster’ boats that merely floated lower in the water.  These ships often had a stateroom in the back and a cargo hold in the middle.

    The LPVs’ layout, however, has changed over time. Later LPVs had a specialised hull form with a typically pointed bow and tail, a small cabin, an engine compartment, and drugs cargo packed into every possible area.  Additionally, the cabin’s sloping sidewalls reduce the craft’s radar profile. The use of fibreglass contributes to their stealthiness overall. This fibreglass structure makes the vessel almost impossible to detect using sonar or radar. And since they move below the surface and are often camouflaged with blue paint, they are very difficult to detect visually. Furthermore, newer models channel the exhaust along the bottom of the hull to cool it before venting it. This makes the boat even less susceptible to infrared detection (source). 

    However, in more modern model adaptations, LPVs have an, even lower profile, with the nose submerged even in calm seas, metal construction rather than fibreglass, and the ability to trim running depth using hydroplanes at the back. The reasons behind these changes are still not clear.

    2.5 Narco-Submarines Today

    Cartels construct the majority of narco-subs in the jungles along the Pacific coast of Colombia. Most of them are presumably built at makeshift shipyards along Colombia’s inner rivers. Apart from detentions in transit, Colombian authorities are now directly targeting the shipyards. However, these facilities are difficult to identify and are often well hidden in lush or remote areas. This tactic is similar to those used in the production of cocaine. 

    Cartels have also established unauthorised submarine factories in nearby nations like Ecuador, Brazil, and Guyana. Authorities have also found connections with the Revolutionary Armed Forces of Colombia (FARC) rebel movement in Colombia, which facilitates and profits from the trafficking and has existed for many years. According to reports, the FARC have been using these vessels since the 80s (source). For instance, the arrest of Harold Mauricio Poveda on November 5, 2010, a crucial Mexican-Colombian link, showed that the FARC were behind the submarine construction. Furthermore, they also discovered that they were partnering with the Sinaloa Cartel to fund their activities (source).

    2.6 Response and Interceptions

    A U.S.-led international coalition made up of the navies, coast guards, and paramilitaries of nearly every country in Latin America is engaged in combat against narco-subs. This is the case of the Joint Interagency Task Force (JIATF) South, a component of SOUTHCOM composed of multiple federal and partner nation agencies and military forces (source). These agencies collaborate to conduct detection and monitoring operations, as well as to provide information that helps law enforcement in the interdiction of illicit trafficking (source). 

    Authorities throughout the Americas have destroyed or seized at least 50 narco-sub boats since 2006. Nevertheless, narco-submarines are still in use and progressing technologically. Recently authorities are seizing these vessels en route to Europe, demonstrating increased range and endurance.

    CGC Jarvis intercepts SPSS.

    Despite the vast financial resources of cartels, the artisan character of the ships and submarines suggests that criminal groups have limited ability to mass-produce vessels. However, LPVs are still capable of regularly delivering drugs, as evidenced by the more than 40 narco-submarine occurrences that authorities have documented in 2019. A 2015 U.S. Foreign Military Studies Office (FMSO) report stated that nearly 80 per cent of narcotics smuggled into the U.S. are transported via maritime lines. Of that 80 per cent, 30 per cent were transported via narco-subs (source). According to a 2019 press release, the US Coast Guard only captures 11% of submarines that transit sovereign waters (source).

    (Source), (source), (source), (source)

    Graph illustrating the evolution of Narco-Subs (LVPs). Source: Covert Shores (HI Sutton), for Foreign Brief.

    3.0 Characteristics

    To recognise a narco-submarine, we can look at certain key characteristics:

    • Submersible Design: Narco-submarines are usually semi-submersible or fully submersible. Semi-submersibles are partially submerged, with only the cockpit and exhaust pipe visible above the waterline. Fully submersibles, however, can submerge completely.
    • Low Profile: These vessels have a low profile on the water, making them difficult to identify from a distance.
    • Long Range: Narco-submarines are capable of travelling vast distances, frequently thousands of miles, to transport illegal drugs from South American production hubs to North American distribution sites.
    • Crew Size: A narco-submarine’s crew is typically minimal, with only a few people in charge of operating the craft and handling the drug cargo. Unmanned narco-subs have also been observed in recent years.
    • Homemade Construction: Traffickers favour building narco-submarines in remote regions. They are frequently constructed of fibreglass or other lightweight materials that make them difficult to detect on radar.
    • Stealth Technology: To avoid detection, certain narco-submarines are outfitted with radar-absorbing materials and soundproofing.

    (Source), (source), (source)

    A Coast Guard Cutter Stratton boarding team investigates a self-propelled semi-submersible interdicted in international waters off the coast of Central America, July 19, 2015. The Stratton’s crew recovered more than 6 tons of cocaine from the 40-foot vessel. Coast Guard photo courtesy of Petty Officer 2nd Class LaNola Stone.

    4.0 Typology

    The artisan nature of narco-submarines means that they are not all the same. However, we can divide narco-submarines into semi-submersible or fully submersible vessels.  

    4.1 Semisubmersibles or Low-Profile Vessels (LPV)

    The majority of ‘narco-submarines’ used by cartels are Low-Profile Vessels (LPV) and are not fully submersible despite having minimal exposure to the water surface. Semi-submersible vessels (Self-Propelled Semi-Submersible or SPSS) are partially submerged, with only the cabin and exhaust visible above the waterline. SPSS are easier to produce compared to completely submerged vessels because they are cheaper, and less complex, requiring less technical effort when manufacturing them. LPVs use Air air-independent propulsion (AIP) or external diesel-run engines, maintaining a snorkel always on the surface which inhibits complete submersion.

    The crew size ranges from 1 to 3 people, and while the average cargo hold is 1.6 tonnes of narcotics, larger LPVs and SFVs can carry up to 10 tonnes of narcotics. 

    (Source), (source)

    4.1.1 Types of LPVs

    Within LPVs, we can distinguish four different types, according to Naval expert H.I. Sutton – author of the blog `Covert Shores´. Sutton recently participated in a podcast for Grey Dynamics where he talks about this topic. 

    The different LVPs he identifies are the following:

    Low-profile vessel with inboard motor:

    These are purpose-built vessels with a very low profile, just a couple of metres above the surface. It has a sailboat-shaped hull with a small cabin roughly in the middle. The engine is located inside. 

    Due to this, we call it an inboard engine which gives rise to the acronym LPV-IM (Low Profile Vessel, Inboard Engine). This is the oldest of the modern types and first appeared in 2005. It is still relevant today but has become less common.

    Low profile and very slender:

    VSVs (Very Slender Vessels) have, since 2017, increasingly popular with drug trafficking organisations. Their defining characteristic is that they are very long and narrow, with a bow that pierces the waves and cuts through them, rather than over them. This feature makes the vessel faster and more manoeuvrable.

    They are typically 1.5 metres long and 1.5 metres wide. Most have outboard engines, giving rise to the acronym LPV-OM-VSV (low profile boat, outboard engines, very slender hull).

    Hybrid go-fast:

    Another category of narco-sub is those that feature a speedboat-style hull but carry it lower in the water. At first glance, it may look like a smuggler’s speedboat, which is a speedboat loaded with extra fuel and narcotics, but it sits much lower. Some have custom-made hulls, but most take a speedboat hull and modify it. 

    According to Sutton, this is easier than building a dedicated boat from scratch and goes faster. It does, however, come at the expense of stealth. In any case, this model has been popular since 2016. The stealthier VSV type mentioned above evolved from this type.

    Very slender vessel with inboard motor:

    Authorities have only intercepted one of this type at sea so far. The Colombian Navy retrieved it from the water in January 2019. The concept is simple: take a standard low-profile boat with an inboard engine and replace it with a VSV hull. This configuration reduces cargo yet appears to be the most stealthy of all.


    We can divide narco-submarines into four categories based on their external characteristics. Although individual vessels vary, almost all fit into these categories. Credits: HI SUTTON via Forbes.

    4.2 Submarines or Fully-Submersible Vessels (FSV)

    Fully submersible vessels are able to submerge completely. This category includes both “true submarines” and “snorkel subs” which keep a mast above water. True submarines were uncommon until the 2000s. Although they can submerge like a navy submarine, they cannot go to the same depths. For instance, while most navy submarines have a test depth between 200 and 300 meters, authorities have not found true submarines that exceed 100 meters. 

    FSVs are either propelled by electric or diesel engines, although the latter has only been reported twice and has higher operational and maintenance costs. FSVs are unusual for two reasons. They are produced less as they are more expensive and complex to manufacture and, if they fail, are more dangerous. Furthermore, they are rarely seen because those that exist, since can operate deeper, are more difficult to detect and capture.

    (Source), (source), (source)

    Profile of a rare fully submersible vessel found in Arauca Rive, Venezuela, April 2022. Courtesy of HI Sutton (Covert Shores).

    4.3 Unmanned Surface Vessels (USV)

    Unmanned Surface Vessels (USVs) are autonomous or remote-controlled vessels that operate on the water’s surface without the presence of a human crew. USVs use a common diesel-powered vessel as their lack of crew allows it to decrease its low-profile characteristic. Spanish authorities have discovered that they often only require the use of a tablet and an app that allows criminals to monitor them remotely, guided by GPS (source).

    Authorities reporters USVs first in 2019 on the coast of Italy and only carrying 37 Kg of cannabis. It is likely that DTOs will invest in them given their autonomous nature and the ability to expand their capabilities. This is because it allows Drug Trafficking Organisations (DTOs) and cartels to avoid reducing recruitment size due to potential arrests. 

    Nevertheless, and as previously reported by Grey Dynamics, the evolution of narco-submarines from 1993 to 2020 indicates that USVs are unlikely to significantly develop in the short term. While USVs have a lot of development in military contexts, the prospects for use in drug smuggling remain low for now.

    4.4 Narco-Torpedoes

    In August 2005, the United States seized an unmanned semi-submersible in the Pacific Ocean.  This particular vessel caught the interest of militaries and law enforcement officials because they discovered that it was manufactured in the shape of a torpedo, filled with narcotics, and carried underwater by another boat.  ‘Narco-torpedoes’ can travel at a depth of approximately 20 to 30 metres. 

    When the authorities approach, the torpedo is released, and it discharges beacons after a certain period to allow recovery by a backup boat when law enforcement has left the area. The ‘narco-torpedo’ vessel is a tactical variation in narcotics transit.  Their main advantage is that they are less expensive to produce than semi-submersibles and their design makes them difficult to detect.  

    (Source), (source)

    5.0 Advantages and Limitations

    Compared to actual semi-submersibles and submarines, LPVs are far less expensive and easier to build. According to reports, LPVs have crossed the Atlantic from Guyana to Spain thanks to their predominant use of air propulsion and snorkels. In contrast, diesel-powered FSVs are probably too expensive for DTOs to adopt as the preferred technique because they have a restricted travel range and must be towed by a larger vessel. As Grey Dynamics already predicted, is unlikely that DTOs have prioritised diesel-powered transport because of the anticipated $1.5 million cost of electric submarines and their limited capabilities. This is because expenses would most likely soar as well as law enforcement efforts at interdiction.

    Furthermore, LPVs don’t need a complex ballasting system to alter the running depth, allowing for more weight and space to be utilised for drug storage. The crew of a narco-sub, unlike submersible craft, does not need particular training and has a decent chance of escaping if something goes wrong. Low-profile ships, on the other hand, are less stealthy than real semi-submersibles or submarines. However, authorities estimate that only about 25% of low-profile vessel excursions are stopped.

    Additionally, LPVs’ current capabilities surpass not only those of FSVs but also USVs. Despite being desirable due to the ability to operate without a crew, authorities have intercepted USVs while going only small distances from Albania to Italy. This shows that this method cannot be used to transport goods over long distances.

    (Source), (source)

    6.0 Areas of Operation

    According to Sutton, the routes these vessels follow are mainly from South America to Central America and beyond. The main route is in the Pacific, from Colombia to Mexico, and from there, the drugs continue overland. However, they have also been seen in the Caribbean and across the Atlantic to Europe as well as Africa (source). 

    Narco-submarines are extremely important tools in the drug trade since they can transport large cargoes and are hard to find. Nearly 80% of drugs smuggled into the United States are transported via maritime lines, according to a U.S. Foreign Military Studies Office (FMSO). Thirty per cent of those eighty per cent were transported by narco-subs. Only around 25% of these submarines, according to the US Coast Guard, have been intercepted (source).

    The following are the main areas of interest:

    6.1 Mexico

    ”El Chapo” Joaquin Guzman was among the first to employ narco-submarines. He hired naval architects to come up with a way to build these comparatively complex ships in rudimentary conditions beneath the dense forest canopy. 

    At the end of June 2023, Mexican authorities seized a semi-submersible carrying 3.7 tonnes of cocaine on the Pacific coast. This was the largest since 2008, a 26-metre-long vessel with two internal engines, an average speed of eight knots and an autonomy of 20 days. It contained 3,734 kilograms of cocaine, which represents the largest shipment seized in 2019 to date.

    The cargo came from Colombia and belonged to the Sinaloa Cartel. Since 2019 authorities have seized six types of submersibles and semi-submersibles while reporting the discovery of eight other vessels with these characteristics on Mexican coasts. In the other five vessels seized, considered by the authorities to be low-profile, the authorities seized 3,634 kilograms of cocaine.

    (Source), (source)

    This is the first vessel of this type to be secured in 2023 and the largest vessel of its size and cargo capacity to be secured in the current administration. Photo: Semar.

    6.2 Colombia

    From 1993 to May 2023, the Colombian Navy had intercepted and seized 228 illegal semi-submersible and submersible devices.

    On May 12, 2023, the Colombian Navy announced that it had captured the largest narco-submarine in the nation’s history. More than three tonnes of cocaine were inside the submersible, which was 30 metres long and 3 metres broad. The Colombian institution reported that 3058 kg of cocaine hydrochloride were recovered in this interdiction, preventing the admission of 103 million dollars to drug trafficking organisations and the commercialization of 7.6 doses on the streets of the world.


    Semi-submersible captured in Colombian waters. Photo: Colombian National Navy.

    6.3 Spain

    The drug-submarine situation in the Atlantic is becoming worse. In November 2019, Spanish authorities seized a 22-meter (72-foot) boat believed to have come from Colombia. It was carrying 3,000 kilogrammes of cocaine and authorities intercepted it near the Galician coast. 

    On March 15 2021, authorities seized another narco-sub. This time however it was Spanish-made. This was the first “narco-submarine” discovered to have been manufactured in Spain. It is a semi-submersible boat with the capacity to smuggle up to 2,000 kilogrammes of drugs.

    On August 27 2021, Spanish police once more apprehended a brand-new kind of drug smuggling vessel. Like the ones seized before, it was highly rare. Experts believe that Spanish smugglers operate uniquely and build extremely different vessels than their rivals in Latin America. Locally, this novel type is referred to as a Ghost Glider (“planeadora fantasma”).

    The ‘Ghost Glider’ fits broadly into the ‘narco-submarine’ category, albeit in its sub-category. Credits: HI SUTTON.

    In 2022, Spanish authorities seized several underwater narco-drones. Each of them was capable of carrying up to 200 kg of drugs and operated through the Strait of Gibraltar (source). That same year, authorities seized another homemade, semi-submersible “narco-submarine” capable of transporting 3,068 kg of cocaine from Brazil to Spain. Authorities estimated that the street value was €123 million. In 2023, authorities found another narco-submarine, this time abandoned and adrift in the Arousa estuary (source).

    (Source), (source), (source), (source), (source)

    Three ‘Types’ of Spanish Narco-Submaries: ‘Vigo’ FSV, ‘Transatlantic’ and LPV, ‘Ghost Glider’ LPV/GFV. Source: H I Sutton via SWJ.

    6.4 Ecuador

    Given its geography, very similar to Colombia, Ecuador is also an ideal place for manufacturing and the starting point for drug trafficking. For instance, on July 3, 2010, Ecuadorian authorities seized a fully submersible and fully operational diesel-electric submarine in the jungles bordering Ecuador and Colombia (source). The vessel had a 31 m (102 ft) long cylindrical fibreglass and Kevlar hull, a 3 m (9.8 ft) conning tower with periscope and air conditioning. It also had a capacity for about 10 tons of cargo, a crew of five or six, the ability to fully submerge up to 20 m (66 ft), and the capability for long-range underwater operations. Ecuadorian authorities confiscated the ship before her maiden voyage (source).

    In 2021, the Ecuadorian Navy captured a homemade LPV designed to transport illegal narcotics, in the Pacific Ocean off Colombia (source). 

    A fully operational submarine built for the primary purpose of transporting multi-ton quantities of cocaine located near a tributary close to the Ecuador/Colombia border (2010). Source: US Drug Enforcement Administration. 

    7.0 The Future of Narco-Submarines

    Until recently, the main purpose of narco-subs was to transport cocaine around Central America. However, according to many policy strategists and planners, there are  several potential future developments:

    • The potential for narco-subs to bypass Mexican Cartels and carry drugs directly to US borders.
    • The potential for narco-subs to carry additional illegal cargo, in particular Weapons of Mass Destruction (WMDs).
    • The mass employment of narco-subs to transport payloads to Europe and Africa on transatlantic voyages. Europe, especially Spain, has become a popular destination for narco-subs in recent years. Spanish authorities have also started to seize locally produced narco-subs. Authorities will likely begin to discover these vessels on their way to other parts of Europe.
    • The mass employment of exterior cargo containers that a narco-sub can discharge nearby. This would potentially eliminate the requirement for regional cartels to meet the ship. DTOs already use these torpedo-like vessels on a limited scale but have significant potential.
    • The development of narco-subs that can operate independently and remotely. Although on a modest scale, such as with the usage of modified surfboards, these types of vessels are already in use by Mexican drug gangs. Authorities have also discovered UAVs in Spain, indicating a potential increase in use. 

    (Source), (source)

    8.0 Conclusion

    Narco-submarines have become increasingly common and standardised, so we can expect this technology to develop further. The amount of money that law enforcement is now spending to thwart these practices has proven sufficient to drive cartel innovation, but insufficient to deter it. Moreover, it stands to reason that, as the technology advances, it will spread to other illicit operations. There is therefore a good chance that autonomous vessels built from narco-subs will spread around the world and circumvent current law enforcement tactics. But as the narcos’ technology advances, we assume that the same will happen with that of authorities, especially in Europe. Governments will therefore increase collaboration and will continue developing new technologies and strategies to counter the cartels.

    Special thank you to HI Sutton for his amazing work on Narco Subs!

    Javier Sutil Toledano
    Javier Sutil Toledano
    Javier is an Intelligence Analyst specialising in South America, Central America and the Caribbean. He graduated in Philosophy, Politics and Economics, with a minor in Peace and Conflict Studies. He recently graduated from an International Master's Degree in Security, Intelligence and Strategic Studies.

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