The torpedo shape has been the default for underwater vehicles for more than a century. It’s cheap to build, easy to seal, and it slides through water well enough that nobody felt much pressure to improve on it. A Berlin company called EvoLogics looked at that consensus and decided the better design was already swimming around Antarctica, eating fish.<\/p>\n
The result is the Quadroin, an autonomous underwater drone shaped like a penguin. Not penguin-themed. Penguin-shaped, down to the spindle profile of the body, because the company’s founder spent years measuring how the actual birds move through cold water. The machine is 44 inches (1,120 mm) long, weighs under 55 lb (25 kg), and tops out at 10 knots (11.5 mph), in a product category where the word “fast” usually means you packed a second battery.<\/p>\n
And the timing of this story is not an accident. On August 19 and 20 the Quadroin goes on display at DALO Industry Days<\/a> in Herning, Denmark, the largest defense exhibition in Scandinavia, run by the Danish Ministry of Defence’s procurement arm. The sales pitch practically writes itself. The Baltic seabed has developed a security problem, and the people in charge of it want cheap, fast, autonomous eyes down there.<\/p>\n Start with the science, because it’s the part of this story that sounds like marketing and isn’t. Dr. Rudolf Bannasch, the EvoLogics founder, has been studying Ad\u00e9lie penguins since the 1980s, including field trips to the Antarctic and years of experiments in wind tunnels and water tanks.<\/p>\n His published measurements, cited in the Journal of Experimental Biology<\/a>, put the drag coefficient of a wingless penguin body as low as 0.03. A cylinder with the same length-to-thickness proportions, aligned with the flow, comes in at 0.85. Same size, same water, and the bird’s shape produces roughly 28 times less resistance than the pipe.<\/p>\n Drag is what your battery spends most of its life fighting, so a shape that cheap to push is a shape that goes farther, or faster, on the same charge. That’s the entire thesis of the Quadroin: EvoLogics says the low-drag body is what lets it hit 10 knots while keeping energy consumption down. Evolution had a very long head start on this design and no committee meetings. The Berliners just took notes.<\/p>\n The company has been taking those notes for a while. It built a concept demonstrator called the AquaPenguin for the automation firm Festo back in 2009, ran an experimental follow-up called the PingGuin, and launched the first real Quadroin in May 2021.<\/p>\n The current generation, unveiled in early 2024<\/a>, is where the machine stopped being a clever science platform and started looking like a working tool. It carries a side-scan sonar for acoustic imaging of the seafloor, plus two full-HD cameras, one angled 45 degrees forward and one pointing straight down, with dimmable LED lights for dark water.<\/p>\n The interesting part is what happens to all that data. The classic survey-drone workflow is swim, record, surface, and hand everything to humans who spend hours reviewing it back ashore. The Quadroin runs an AI object-recognition module directly onboard, flagging objects in the sonar and video feeds live, during the mission. A front-looking sonar feeds an automatic collision-avoidance system, so the drone dodges obstacles on its own too.<\/p>\n The rest of the spec sheet is compact and practical. Maximum depth of 492 ft (150 m), up to 6.6 lb (3 kg) of payload, and a lithium-ion battery that delivers more than 10 hours of runtime at its 4.5 mph (7 km\/h) cruise after a charge of under six hours. A Nortek Nucleus1000 navigation package keeps track of where it is, and a retractable antenna handles WiFi, radio and GNSS whenever it pokes above the surface. The design took the Robotics prize at the Deep Tech Berlin 2024 Award, which is the kind of thing that matters less than a contract but more than nothing.<\/p>\n The Quadroin’s origin story has nothing to do with navies. The first prototypes were developed with the German research center Hereon for the Helmholtz Association’s MOSES initiative, an Earth-observation program, and their job was hunting ocean eddies. The plan called for a swarm of up to 10 of them, fitted with probes measuring temperature, pressure, oxygen, conductivity and fluorescence, scanning the water column in formation.<\/p>\n That swarm bit is not decorative. The drones coordinate through acoustic links to surface gateways, with live status updates and mission control while submerged. Underwater acoustics happens to be EvoLogics’ home turf: it’s the same Berlin outfit whose dolphin-inspired communication tech shows up in Germany’s Greyshark drone submarines<\/a>, a much larger machine built for months-long patrols.<\/p>\n EvoLogics also coordinated BONUS SEAMOUNT, a multi-country research project that put autonomous vehicles to work surveying the Baltic seabed, studying its integrity and tracking groundwater seeping up through it. So the company has years of practice running drones over the exact patch of seafloor that has since become the most nervously watched real estate in European security.<\/p>\n Since October 2023, at least eleven cables in the Baltic region have been severed or damaged. The running tally<\/a> includes power links, telecom lines and a gas pipeline, and the pattern investigators keep describing is a commercial vessel dragging its anchor across the seabed. In one November 2024 case, authorities tracked an anchor drag of roughly 300 kilometers. Police have concluded some incidents were sabotage, found others accidental, and left several in open proceedings, which is about as settled as attribution gets in international water.<\/p>\n The institutional response has been fast by NATO standards. The alliance launched Baltic Sentry in January 2025, putting frigates, patrol aircraft and naval drones on the problem. Then in February 2026, eight allies including Denmark, Germany, Finland and Sweden signed a letter of intent to push Task Force X-Baltic<\/a> into its second phase, moving from experimental fleets of autonomous systems to nationally owned ones that NATO can task for persistent coverage.<\/p>\n Read that again from a Berlin sales office: eight governments just committed, in writing, to buying more AI-driven underwater autonomy for the Baltic. Three days after this article goes up, EvoLogics will be standing at Stand 2375 in Herning with the Quadroin, its Sonobot surface drone, a diver-navigation system, and what the company describes as solutions for critical infrastructure, in front of exactly those procurement people. The company has also opened a U.S. sales office in Yorktown, Virginia, and showed at Undersea Defence Technology in London this April, so the defense circuit is clearly the plan, not a coincidence.<\/p>\n A word of honesty about what’s on the table, though. EvoLogics has published no military contract for the Quadroin, and a 55 lb drone rated to 492 ft is a coastal surveillance and survey tool, not a weapons system. What it offers navies is the boring, valuable thing: a small machine that covers seabed fast, recognizes what it sees without waiting for a human ashore, and costs a fraction of putting a crewed vessel on the same patrol line.<\/p>\n The Quadroin also slots into a pattern this site keeps running into: the machines being sent under the sea increasingly look like things that already live there. China has run a manta-ray-shaped drone<\/a> through a mine hunt in near-total darkness. Norway keeps a 20-foot drone snake<\/a> living on the seabed, checking pipelines and cables. The cylinder had a century-long run as the only shape in the water. Judging by what’s swimming out of the labs lately, that run is ending, and in Herning this week, the penguin gets to make its case to the people holding the checkbooks.<\/p>\n","protected":false},"excerpt":{"rendered":" The torpedo shape has been the default for underwater vehicles for more than a century. It’s cheap to build, easy … <\/p>\nA penguin body has 28 times less drag than a pipe<\/h2>\n
The sonar reads itself before the drone surfaces<\/h2>\n
It was built to chase whirlpools, not submarines<\/h2>\n
The Baltic keeps losing cables, and the buyers are in Herning<\/h2>\n