The so-called Autonomous Low-Profile Vessel ranges thousands of miles. The Marines could launch an ALPV from Hawaii and sail it all the way to the first island chain, which stretches between Japan and The Philippines and is expected to be the front line of any major fighting between the United States and China, potentially over Taiwan. The Marine Corps is transforming itself from a relatively conventional land combat force to a missile-heavy, mobile maritime organisation designed to use Pacific islands as bases of fire against Chinese forces.

One of the biggest challenges in deploying the ALPV is safety. Operators based halfway around the world would need to plot a course for the vessel that avoids the busiest shipping lanes – and possible collisions with civilian ships. It’s imperative that the vessel “is not in conflict with commerce and other things out there,” Doran said.

The semi-submersible is designed to be simple to operate. For initial trials in February, the Marines spent three weeks training a cook to pilot the vessel via satellite. Doran compared the ALPV’s operating system to a smartphone app. 

The early experiments have been encouraging, and enthusiasm is building. “The Marines wanted it yesterday,” Doran said of the semi-submersible. And for good reason. Many of the other craft the Marines are counting on for island supply missions are unreliable – or running into developmental problems. 

The Marines fly hundreds of long-range MV-22 Osprey tiltrotors which are ideal for island supply flights when they’re working, but the controversial rotorcraft were grounded for months following a fatal crash in November. It was hardly the V-22’s first safety crisis – and it probably won’t be the last.

The Marines are also working with the Navy to develop a new class of small, inconspicuous landing ship that, in theory, could sail between islands in the western Pacific Ocean without attracting the attention of Chinese forces as it would resemble a merchant vessel under any but close inspection. But construction of the first of potentially dozens of ships has fallen two years behind schedule, to 2025 at the earliest, amid a worrying spike in costs.

Out on the technological fringes, the Pentagon was tinkering with a couple of concepts for seaplanes and floatplanes – aircraft types the US military hasn’t operated in decades. But none of these initiatives are making much headway.

While the ALPV’s main mission would be shuttling supplies to distant island outposts where the Marine Corps plans to establish missile bases as part of its new island-hopping strategy, it’s also possible to arm the low-slung vessel. USMC testers have concluded it’s possible to fit the ALPV with a pair of 800-pound Naval Strike Missiles, which can hit ships and targets on land from as far as 100 miles away.

At least one of the ALPVs is heading to Okinawa, Japan – the main base for the III Marine Expeditionary Force – for further testing in increasingly realistic conditions. If all goes well, the Marines might start purchasing narco-boats in large numbers in the next few years.

If the Marines are smart, they’ll do what the cartels have done – and keep the vessels as simple as possible so that they can be produced quickly, at scale and for a reasonable cost. The cartels need that capacity because they can expect law-enforcement patrols to intercept a certain percentage of their drug-running semi-submersibles. The Marines, likewise, can expect Chinese patrols to intercept some of their semi-submersibles.

Overall, though, the ALPV is a good idea. Done well, it could help make the Marines’ island-hopping plans for war against China a lot more successful.