Almost everything about building a submarine comes down to one job: keeping the ocean on the outside. The pressure hull that does it is thick, precision-welded and brutally expensive, and it is a big reason undersea programs eat budgets and calendars whole. So the most interesting thing about the newest American drone submarine is that its builders skipped that job on purpose.<\/p>\n
On August 10, Raytheon announced<\/a> that HADALUS, a 34-foot unmanned undersea vehicle it developed with Composite Energy Technologies, a composites specialist from Portsmouth, Rhode Island, had completed a series of missions on a U.S. Navy undersea test range. During the exercise, the drone launched a payload while submerged. According to Raytheon, that was the first time the Navy has watched this particular combination, the vehicle and its integrated launcher, work together in the water.<\/p>\n And the machine that pulled it off went from a sketch on paper to a working prototype in the ocean in less than 18 months. In the undersea business, 18 months is roughly how long the paperwork takes.<\/p>\n Raytheon describes the HADALUS structure as a free-flooded, all-carbon-fiber exoskeleton. Free-flooded means exactly what it sounds like. Seawater flows straight through the vehicle’s skeleton instead of being held back by a sealed hull.<\/p>\n A conventional submarine, crewed or robotic, wraps its important parts inside a pressure hull, a reinforced vessel that keeps the interior at something survivable while the ocean squeezes from outside. That hull has to be designed, certified and welded to standards that make aerospace look relaxed, and the deeper you want the vehicle to go, the worse the math gets.<\/p>\n A free-flooded design mostly opts out of that fight. The structure does not have to resist a huge pressure difference, because there barely is one; the water inside sits at the same pressure as the water outside. In vehicles built this way, the gear that genuinely needs to stay dry typically gets its own small sealed housings, which is a far cheaper problem to solve than one giant certified cylinder.<\/p>\n That is the logic behind the price pitch. Raytheon says HADALUS is designed to cost roughly one-third to one-fifth as much as comparable long-endurance vehicles. The fine print: the company has not named those comparable vehicles or published a dollar figure of its own, so the claim is a ratio with no denominator.<\/p>\n The engineering behind it is sound, though. Delete the pressure hull and you delete one of the most expensive items on a submarine’s bill of materials.<\/p>\n The rest of the spec sheet, all of it from the manufacturer via the release carried by Naval News<\/a>: 34 feet long, a six-foot cross section, and an endurance of more than 2,000 nautical miles, which works out to about 2,300 statute miles of water covered without anyone topping it up.<\/p>\n The timeline is the other half of the story. Per the announcement, Raytheon and CET covered the development out of their own pockets, funding the vehicle’s design and build, the launcher integration, the sonar and electronics, and the full system testing that led up to the Navy exercise. No program of record, no government development contract named in the release.<\/p>\n Jen Gauthier, vice president of Naval Systems & Sustainment at Raytheon, framed the demonstration as one step in a longer roadmap toward autonomous undersea systems that are “far less detectable than surface platforms.”<\/p>\n This also was not the pair’s first sprint. ExecutiveBiz reports<\/a> that the two companies put an extended-range test vehicle in the water in Narragansett Bay back in July 2025, running Navy-developed autonomy software the service makes available to industry. That earlier vehicle went from concept to demonstration in four months.<\/p>\n On paper this is an odd pairing. RTX, Raytheon’s parent, booked more than $88 billion in sales last year and employs over 180,000 people. CET is a composites manufacturer working out of a coastal Rhode Island town. The partnership works because each side brought what the other lacked: CET the carbon-fiber vehicle architecture, Raytheon the sonar, mission systems and integration muscle.<\/p>\n Neither company has said. The release confirms a payload came out of the submerged vehicle on a Navy undersea test range during a service exercise. What that payload was, how big it was, and whether it swam, floated or sank is not public.<\/p>\n The concept it serves is spelled out, though. Raytheon frames HADALUS as a step toward a single unmanned platform that can find a target, pick it up again after losing contact, and then go after it, all within one mission. Right now those jobs tend to be split across separate assets, often with hours between the steps and a tasking chain in the middle.<\/p>\n America has been busy building the detection half of that picture. An Anduril seabed sensor network put submarine drones on a Navy screen within seconds<\/a> during a six-week exercise across two continents earlier this year, with no human relaying the data. A drone that can hear something, confirm it and act on the spot is the obvious next block in that wall.<\/p>\n One thing to keep straight: submarines have been launching things underwater for more than a century. Torpedoes are the whole franchise. The first claimed here is narrower, and Raytheon scopes it carefully: the Navy had not previously seen this integrated launcher-and-vehicle package, on this class of drone, operating in the water.<\/p>\n Most of the underwater drones the Navy has tested lately live with one hard constraint: the 21-inch torpedo tube of an attack submarine. Fit through the tube and you can ride along on any boat in the fleet, which is why so many recent vehicles are skinny, torpedo-shaped machines.<\/p>\n HADALUS plays a different game. A six-foot cross section is more than triple the diameter of a heavyweight torpedo, which puts it in extra-large territory, where a drone stops being a submarine’s accessory and becomes its own platform. That is the same neighborhood as the long-endurance machines that can park on the seabed for more than two weeks<\/a> watching a single cable.<\/p>\n Getting a six-foot-wide machine to where it is needed is its own problem, and CET has a specific answer. The company builds the HADALUS family as what it calls Flat Pack AUVs, vehicles engineered to ship in standard containers and be assembled at the point of deployment. DARPA’s Manta Ray ran the same play<\/a>, crossing the country in five shipping containers and getting bolted together dockside in a couple of days.<\/p>\nThe water comes in on purpose<\/h2>\n
Under 18 months, and the companies paid the bill themselves<\/h2>\n
So what did it actually launch?<\/h2>\n
Six feet across is the tell<\/h2>\n