The Autonomous Submarine That Wasn’t Real Yet
When I wrote the autonomous submarine at the heart of The Apex Code‘s opening chapters, it was speculative, grounded in active engineering, but nothing quite like it existed yet. That’s changed faster than I expected. Two real autonomous submarines, one American and one British, have gone from prototype to delivered hardware in the years since, and both, unsurprisingly, land somewhere close to what the story demanded.
The Autonomous Submarine Idea Isn’t New
The concept itself isn’t new. The first self-propelled, uncrewed underwater weapon dates back to 1866, when Robert Whitehead built the first “automobile torpedo,” a compressed-air-driven device that ran a preset course underwater with nobody aboard to steer it. That’s a genuinely old idea. What we’d now recognize as an actual autonomous underwater vehicle came almost a century later, in 1957, when the University of Washington’s Applied Physics Lab built SPURV; the Self-Propelled Underwater Research Vehicle, to study Arctic waters, funded by the Office of Naval Research. For decades after that, autonomous underwater vehicles stayed small, scientific, and unarmed. A genuinely large, weapons-capable, fully autonomous submarine is a more recent development; just in the last two or three years, after roughly a century and a half of the underlying idea waiting for the engineering to catch up.
The American Version: Boeing’s Orca
The U.S. Navy’s Orca XLUUV (Extra Large Uncrewed Undersea Vehicle) is built by Boeing, based on more than a decade of work on their Echo Voyager prototype. It’s roughly 85 feet long, capable of operating fully autonomously for months at a time, and has a range of 6,500 nautical miles thanks to a hybrid power system. Boeing delivered the first Orca to the Navy in December 2023, with more following since. Its modular payload bay is designed to support a wide range of missions; mine countermeasures, anti-submarine warfare, intelligence and reconnaissance, and general seabed operations, all without a crew, and without a support ship needed to launch or recover it. That last detail matters more than you might think: it means each vessel can be sent out on any type of mission, from dock-to-dock, with nothing else required to bring it home again.
The British Version: MSubs’ Cetus
Across the Atlantic, a much smaller company has been building something just as significant. MSubs Ltd, based in Plymouth, England, designed and built the Royal Navy’s first crewless submarine under Project Cetus. Named after a sea monster from Greek mythology, the demonstrator, christened XV Excalibur, launched in early 2025. At 17 tonnes and roughly 12 meters long, Cetus is smaller than Orca, but the Ministry of Defence has been explicit about one thing: it’s built to dive deeper than any vessel currently in the Royal Navy’s fleet, with a design brief centered on protecting critical undersea infrastructure and monitoring sub-sea activity nobody’s supposed to know about.
Where The Apex Code Picked Up the Thread
The fictional autonomous submarine at Arch Cape in The Apex Code sits somewhere between these two real vehicles; American in scale and weapons capability, but built around the same core idea both Orca and Cetus are chasing: a machine that can operate for extended periods, far from any human hand on the controls, making its own decisions to achieve what it was programmed to do. That’s the property that makes it fertile fictional territory. A vessel with no crew to override it, or to notice when its programming stops behaving the way it should.
Neither of these programs existed in their current form when I wrote that opening chapter. I just knew that the idea was going to come; a machine that can act underwater without anyone at the controls, finally catching up because of modern engineering, and that felt like a great place for a story like this one to start.