Seven semi-submersible “narco-subs” have been found in recent months drifting at sea or washed up on the shores of Pacific Island countries (PIC) carrying illicit drugs bound for Australia and New Zealand, according to the ABC.

The US Drug Enforcement Administration have reported that organised crime groups on both sides of the Pacific Ocean are increasing their activity in PIC, as these nations function as transhipment and re-exportation hubs between Australia, New Zealand and the Americas.

Of the seven vessels discovered since August 2024, only one was successfully intercepted, with the rest appearing to be abandoned after offloading.

While narco-subs have long been used by Latin American cartels on shorter, less complex routes, their recent appearance across the Pacific suggests these networks are now capable of operating far further afield than previously imagined.

As a result, authorities across Oceania are confronting a new trafficking method—one that is exceptionally difficult to detect, intercept and control.

Maritime law experts warn that the current counternarcotic strategies and legislation across the Pacific are outdated and ill-equipped to respond. As enforcement struggles to keep pace, narco-sub technology is rapidly improving.

In July 2025, the Colombian Navy intercepted the most advanced narco-sub to date.

Categorised as an Autonomous Underwater Vehicle (AUV), the uncrewed vessel—equipped with a GPS device, satellite systems, multiple Starlink antennas and surveillance cameras—may be the first indicator that international drug trafficking is entering a new autonomous chapter.

AUVs could dramatically reduce the role of the weakest link in transnational drug smuggling, human operators.

​​The evolution of narco-sub technology

Professor Víctor Manuel Sánchez Valdés, a researcher of public security and organised crime from the Autonomous University of Coahuila, told Farrago the reasons behind the constant technological advancements made by transnational cartels:

“The key lies in the high profitability of the business. Finding more efficient and safer transport methods translates directly into greater profits, which incentivises constant innovation.”

“To achieve this, criminal organisations not only experiment empirically, but also rely on highly qualified professionals, including engineers and specialised technicians.”

While a fully submersible vessel was discovered in Venezuela as recently as 2022, most traffickers seem to still rely on semi-submersibles, which operate mostly under the ocean’s surface, significantly reducing their physical, acoustic and thermal profiles. This makes them incredibly difficult to detect through aerial or maritime surveillance.

Professor Alexander Gillespie, an international law expert from the University of Waikato, told Farrago that these emerging smuggling methods are just the tip of the iceberg and that “there will be a lot more that they haven’t found.”

Estimates from MIT suggest it costs around $2 million dollars to make these semi-submersibles, yet Professor Gellespie says these costs are negligible compared to the profits generated in Australian and New Zealand’s drug markets.

Uniquely Profitable

The latest United Nations World Drug Report reveals that Australia has the highest rates of cocaine consumption in the world, with 4.5 per cent of Australians consuming the illicit substance, doubling that of the rate in the US. Furthermore, The Guardian has reported that the cost of cocaine in Australia is between three and six times higher than the US. These factors are why transnational criminal organisations are willing to direct a significant amount of resources to meet demand.

Professor Gillespie highlighted that the scale of drugs passing through the Pacific is increasing, and that, “the busts that are happening in the Pacific right now are just mind blowing and the trend each year as they just get bigger and bigger.”

In New Zealand, customs officers have been consistently stopping the same amount of methamphetamine each week—for the past year—which once totalled the country’s entire annual seizures of the drug in 2014.

Since January, 2.6 tonnes of cocaine worth $780 million was apprehended alongside an Ecuadorian crew in Fiji, which was suspected to have been originally transported to the island via a narco-sub that is yet to have been located.

Also, 11.5 tonnes of cocaine worth $3.4 billion was discovered by French Polynesian authorities across three seizures, two of which were suspected of being bound for Australia and New Zealand.

The Pacific; an Easily Exploitable Region

The emergence of what has been dubbed the “Pacific drug highway” is partly caused by PIC having less policing and prosecuting capabilities than Australia and New Zealand. Organised crime groups have exploited vast, under-patrolled areas while infiltrating local communities, contributing to an increase in drug use and associated crime.

One of the ships that was intercepted near French Polynesia was allowed to continue on its course without any arrests being made. The five tonnes of cocaine it was carrying were dumped into the sea.

French Polynesian President Moetai Brotherson explained to the ABC that they were not prepared to prosecute the crew due to already overcrowded prisons.

Professor Gillespie highlighted the significance of these lack of policing resources:

“A lot of the Pacific isn’t just developing. It’s the least developed […] and the politics at the international level right now, is about giving less to these countries rather than giving more,” he said.

“If you want to secure the region, you have to make sure that the police and security in the Pacific is of a much greater standard than what it is right now […] You’ve got to give them the resources that they need to police.”

Professor Natalie Klein, an expert on the law of the sea, explained to Farrago that gaps within legal frameworks are also contributing to a weak security structure in the region. Specifically, many PIC are not parties to the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, 1988.

“It’s important in terms of creating the international law framework that will allow a country to prosecute somebody who is not one of their nationals, who is not necessarily located in their territory... but for anyone who enters their territorial sea or comes into their maritime areas.

“As a preliminary matter, if [those] PIC became parties to that treaty, the first thing they have to do is really just adopt the national legislation to make sure that they’ve got laws in place that will criminalise this activity.”

Professor Klein also highlighted how these treaties contain obligations around prosecution standards and information sharing that are useful to create stronger counternarcotic strategies.

She expects that becoming a party to these treaties will inadvertently deter countries in the region from adopting tactics pursued by the US in relation to the targeted killing of suspected drug traffickers, as such strategies flaunt long-established rules of international law.

This is of particular concern considering that the opposition leader in the Solomon Islands, Matthew Wale, recently praised the US approach.

The Ever-Evolving Game of Cat and Mouse

These developments occurring in how drugs are trafficked to the Pacific point to a rapidly shifting counternarcotic and security landscape in the region.

While it is uncertain how governments within the region will respond to these new threats, Professor Klein warns that the use of autonomous technology in global drug trafficking is no longer hypothetical.

“It’s going to happen. It’s just a question of how well we’re going to be able to develop the technology to detect those types of vehicles and then have the resources to deploy to actually go and seize it at sea.”

AUVs remove the human element, which reduces labour costs, creates more room for cargo and removes risk of potential informants when intercepted.

These uncrewed vessels have the potential to move slower across longer and less monitored routes, they could wait out patrols, loiter near rendezvous points and if one is about to be intercepted, the owners could scuttle (deliberately sink) the subs from afar.

“If you don’t even have the basic legal framework when there are people on a ship,” Professor Klein said, “how are you going to manage when there are no people?”

Some quotes have been translated to English  

Image source:  ABC Pacific