Portuguese Navy Neutralises Atlantic Narco-Sub, Seizes 1.7 Tonnes of Cocaine

Portuguese task force cuts short Atlantic cocaine run by semi-submersible

A multi-agency task force led by Portugal’s Polícia Judiciária (PJ) and Navy has intercepted a home-built semi-submersible laden with more than 1.7 tonnes of cocaine nearly 1 000 nautical miles west of Lisbon. The covert vessel, often described as a “narco-submarine”, was stopped during the first days of November in Operation El Dorado, an international mission that also involved Britain’s National Crime Agency (NCA) and the United States Drug Enforcement Administration (DEA) and Joint Interagency Task Force South (JIATF South).

A high-seas takedown

• Acting on intelligence relayed by Lisbon-based MAOC-N, Portuguese naval assets shadowed the low-profile craft as Atlantic weather deteriorated.• Boarding teams from a naval patrol ship moved in once the crew’s attempts to evade surveillance failed.• Four men—two Ecuadorians, one Venezuelan and one Colombian—were arrested without resistance.

Investigators say the cocaine was destined for distribution hubs on the European mainland after first landfall on the Iberian Peninsula. Packaging and labelling recovered at the scene point to South American criminal networks that have increasingly turned to hard-to-detect semi-submersibles for trans-Atlantic shipments.

Vessel lost, cargo saved

Bad weather and the craft’s fragile fibreglass construction ruled out towing the 17-metre boat to port. After the narcotics were transferred to a navy vessel, the semi-submersible flooded and sank, a scenario officials had anticipated. The crew were flown to the Azores, where a criminal court in Ponta Delgada has ordered them held in preventive custody while the PJ expands its inquiry.

Second narco-sub capture of the year

The seizure is Portugal’s second encounter with a drug-running semi-submersible in 2025. In March, Operation Nautilus netted a 6-plus-tonne haul roughly 900 kilometres south of the Azores. Until that raid, Portuguese forces had never brought a narco-sub to heel in the Atlantic.

Law-enforcement analysts note that the two cases sketch a clearer picture of the new maritime corridor: boats depart hidden rivers or mangrove inlets on the northern coast of South America—many reports point to Brazil’s Amazon delta—then steer northeast across the Atlantic before angling toward the Iberian Peninsula or, alternately, North Africa.

Why semi-submersibles?

Home-built craft that ride barely above the waterline are cheaper than fully submersible submarines yet difficult to detect with conventional radar. A vessel may carry up to 10 tonnes of cocaine, and even if one is lost, the profit margin on those that succeed remains huge for cartels. The surge in Atlantic captures reflects both the growing popularity of this transport method and the stepped-up sharing of satellite, aerial and signals intelligence among European and American agencies.

Legal road ahead

Under Portugal’s drug-trafficking statutes, the four detainees could face sentences of up to 12 years if convicted. Prosecutors have already requested assistance from authorities in Ecuador, Venezuela and Colombia to map the chain of command behind the voyage. The PJ is also analysing navigation equipment recovered from the wreck to reconstruct the route and rendezvous points.

Regional implications

Portugal sits astride key shipping lanes between the Americas and Europe, making the country a natural frontline in the fight against maritime cocaine smuggling. Successive Atlantic seizures this year have bolstered Lisbon’s standing inside MAOC-N, which coordinates anti-drug efforts for seven European states. Officials believe the latest bust will further justify investment in long-range patrol vessels and airborne sensors—a priority item in next year’s defence budget.

While authorities celebrate the haul, they warn that each interdiction is only a single blow in a prolonged contest. "Interception capacity must keep pace with the ingenuity of transnational crime," a PJ spokesperson said in a written statement. Recent EU and UN reports suggest that up to 250 tonnes of cocaine may still reach European shores annually, generating billions in illicit revenue.

What comes next

For now, forensic teams are cataloguing the seized bales and tracing chemical markers that could link the shipment to specific laboratories in South America. If investigators firmly connect the cargo to a known cartel, the court case in the Azores could become a touchstone for future extradition and asset-freezing requests.

Operation El Dorado underscores that the Atlantic narco-sub phenomenon, first spotted off Spain’s Galician coast in 2019, is no longer a rarity. With two captures inside eight months, Portuguese authorities expect more attempts—and vow that the ocean “will not be a safe highway” for traffickers.