Uncrewed and Under the Radar: How AUVs Transform Drug Smuggling

25 Nov 2025 12:54 PM

Drug traffickers are constantly innovating to increase profitability and lower operational risk. Their experimentation with uncrewed semi-submersible technology presents a predicament for counternarcotics strategies centred on deterrence.

Semi-submersible vessels, often referred to as ‘narcosubmarines’, have become a convenient and effective means for Latin American transnational criminal networks to transport narcotics such as cocaine to international markets. In July, the Colombian Navy reported that 10 semi-submersibles had been detected across Latin America in the first half of 2025 alone, though this likely represents only a small fraction of those in operation.

In recent years, these vessels have been detected increasingly further afield. In 2019, a semi-submersible from Brazil was discovered in Europe for the first time, proving their ability to complete transatlantic crossings. Since then, several have been intercepted off the Iberian Peninsula. In March, an empty vessel washed ashore in Sierra Leone, indicating the use of semi-submersibles to move drugs from South America to West Africa. They have even been detected in the middle of the Pacific Ocean, bound for markets in Australia and New Zealand, some 4,000 miles from their point of departure in Colombia.

The volume of drugs they carry also appears to be rising. In April, the Portuguese Navy intercepted a semisubmersible in the Atlantic Ocean carrying 6.5 tonnes of cocaine, the largest amount on record. Such seizures demonstrate how criminal networks continually innovate, adopting new technologies to increase range, carry greater loads and evade interdiction in pursuit of higher profits.

The latest technological development may be even more significant. On 2 July, the Colombian Navy captured an uncrewed semi-submersible off the coast of Tayrona National Park in Colombia’s Magdalena department. It was described by the Centro Internacional de Investigación y Análisis Contra Narcotráfico Marítimo (CMCON, International Centre for Research and Analysis Against Maritime Drug Trafficking) as an Autonomous Underwater Vehicle (AUV) and is the most advanced autonomous prototype of this nature discovered to date. The vessel was empty, indicating that it was likely undergoing a final test phase before being used to transport drugs.

The emergence of uncrewed semi-submersibles carries major implications for counternarcotics strategies centred on interdiction and deterrence, particularly as tensions ramp up in the Caribbean Sea.

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