{"id":22173,"date":"2026-10-06T09:30:29","date_gmt":"2026-10-06T13:30:29","guid":{"rendered":"https:\/\/www.autonocion.com\/us\/?p=22173"},"modified":"2026-10-06T05:46:41","modified_gmt":"2026-10-06T09:46:41","slug":"drone-submarine-payload-rehearsal","status":"publish","type":"post","link":"https:\/\/www.autonocion.com\/us\/drone-submarine-payload-rehearsal\/","title":{"rendered":"A 39.4-foot drone submarine turned up at a NATO exercise in Portugal carrying a rig whose only job is rehearsing a payload drop, with nothing live leaving the hull while engineers read the telemetry, and the US Navy has already taken delivery of the same long version"},"content":{"rendered":"

Car companies don’t put people in the cars they crash into walls. They strap in dummies, run the violent part, and read the sensors afterward. Navies work pretty much the same way with weapons, and we just covered an 18-foot Turkish drone boat<\/a> that spent its early trials with an inert lump bolted in where the warhead goes.<\/p>\n

Now it’s a submarine’s turn.<\/p>\n

The Speartooth, an Australian drone submarine we wrote about in June<\/a> when the US Navy took delivery of its first one, turned up at a NATO exercise in Portugal in September fitted with hardware whose whole job is to pretend to release a payload. Janes<\/a> spotted it there and published its report on September 16.<\/p>\n

The exercise was Bold Machina 2026, which ran from September 7 to 15 at the Lisbon Naval Base in Alfeite, Portugal. NATO<\/a> describes BOMA as a small-scale experimentation event where its maritime special operations community tests new technology alongside industry and academia, and the 2026 edition focused on crewed and uncrewed systems for long-range strike and reconnaissance, underwater communications, and counter-drone gear for small boats.<\/p>\n

So what was a drone submarine doing at a special forces exercise?<\/h2>\n

Mostly, looking at things. The boat in the water for Vignette 1 of the exercise, a scenario called Operate the Machine, was the 39.4-foot configuration with two payload modules installed, on a hull 3.28 feet across. Janes reports the primary aim was intelligence, surveillance, and reconnaissance, which is defense-speak for going somewhere quietly, collecting data, and coming home with it.<\/p>\n

The new hardware was a canister injection system, fitted to simulate a payload release. In plain English, the boat carried a rig that rehearses pushing something out of the hull without anything live on board, so the engineers get their data, the operators get their practice, and the only thing that actually leaves the boat is telemetry.<\/p>\n

No torpedo was fired at BOMA. Janes is explicit that the canister setup simulated the release, and frankly, that’s the right order of operations. You rehearse the drop until it’s boring, and then somebody signs off on trying it with something that explodes.<\/p>\n

A Eurobotics representative told Janes the two-module layout could also suit a harbor attack, meaning the boat slips into a harbor to release a payload or resupply whoever’s waiting there. The same representative declined to share payload figures, but said a one-way version carrying an explosive payload could “put out of service” a frigate-type vessel. That’s a vendor describing a hypothetical at a military exercise. Nobody ran that test in Portugal, and I’d file the frigate claim under marketing until somebody demonstrates it.<\/p>\n

How does it find its way around down there?<\/h2>\n

GPS doesn’t work underwater. Satellite signals are weak radio waves, and water soaks them up within a few feet of the surface, so a submerged drone has to keep track of its own position some other way.<\/p>\n

Per Janes, the Speartooth does it with a Doppler Velocity Log, a sonar sensor, and an inertial navigation system. The DVL pings sound off the seabed to measure how fast the boat is really moving over the ground, and the INS is basically a box of gyroscopes and accelerometers that adds up every turn and nudge since the last known position. Neither is perfect, and small errors pile up the longer you stay down, which is why the boat can optionally come up, grab a satellite fix, and duck back under, according to the Eurobotics representative who spoke with Janes.<\/p>\n

If you’ve ever watched your phone’s blue dot wander around a parking garage, you’ve seen the same problem at consumer scale. The Speartooth just solves it with hardware that, I’d wager, costs more than your car.<\/p>\n

The catalog numbers don’t quite match the boat<\/h2>\n

Eurobotics is the German company that sells and builds the Speartooth in Europe as the partner of C2 Robotics, the Australian firm that designed it, and its official spec sheet<\/a> lists two configurations. The longer one comes in at 37.7 feet and 2,535 pounds without payload, with 84.8 cubic feet of payload volume. The hull Janes saw at Alfeite ran about 39.4 feet against the 37.7 on that sheet, and I’m not going to pretend those are the same line item, because neither company has said they are.<\/p>\n

The published ratings give a top speed of 7 knots, about 8 mph, and a range north of 575 miles on battery power. Extra battery packs can go into the payload bay to stretch that further, per the same sheet.<\/p>\n

Then there’s the depth figure. The European sheet lists a rated depth of 19.7 feet, roughly the deep end of a decent municipal pool, and that’s the only depth number Eurobotics publishes for this configuration. My guess, and it’s only a guess, is that the public brochure is deliberately boring, because interesting performance figures rarely survive the trip to a marketing page.<\/p>\n

\n
\n
ACTIVE<\/div>\n
Measured at BOMA 2026<\/div>\n
39.4 ft<\/div>\n
Two payload modules installed on a hull 3.28 feet across, per Janes at Alfeite, Portugal.<\/div>\n<\/div>\n
\n
European catalog, long config<\/div>\n
37.7 ft<\/div>\n
2,535 pounds without payload and 84.8 cubic feet of payload volume, per the Eurobotics spec sheet.<\/div>\n<\/div>\n
\n
Catalog range<\/div>\n
>575 mi<\/div>\n
At a listed top speed of 7 knots on silent direct-drive electric propulsion.<\/div>\n<\/div>\n
\n
Catalog rated depth<\/div>\n
19.7 ft<\/div>\n
The only depth figure Eurobotics publishes for the European configuration.<\/div>\n<\/div>\n<\/div>\n

If you’re wondering why an Australian boat with a German sales operation matters to anyone on this side of the Atlantic, the US Navy already owns Speartooths. The service took delivery of its first one back in May, and it ordered the long, two-module configuration specifically. So whatever this canister rig teaches in Portugal, it’s safe to assume the lessons won’t stay in Portugal.<\/p>\n

Janes photographed the two-module Speartooth pierside at Alfeite on September 11, four days before Bold Machina 2026 wrapped up, and published its report from the exercise on September 16.<\/p>\n","protected":false},"excerpt":{"rendered":"

Car companies don’t put people in the cars they crash into walls. They strap in dummies, run the violent part, … <\/p>\n

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