Defense technology is rarely associated with speed either in the water or on a cap table. But AndrenaM, a young startup building AI-powered sonar systems, has upended both. The company closed its $10 million seed round in just 36 hours, an unusually rapid timeline as investors see the need to upgrade undersea surveillance with modern tools.
Led by First Round Capital and backed by Also Capital, Long Journey, Homebrew, Banter, 201, Wavefunction, and the Colorado School of Mines Venture Fund, the round gives the startup the resources to double its team, accelerate deployment, and build its own custom hardware. For a company that only began operations in 2024, the velocity is striking.
AndrenaM was founded in Hawthorne, California, by Matej Cernosek and Alex Chu, who first met during their freshman year at the Colorado School of Mines. Both studied mechanical engineering. After graduation, Cernosek joined SpaceX, while Chu took roles in robotics and software engineering at Qualia, a real estate technology firm. They reconnected with a shared vision: modernizing the ocean’s least visible but most strategically vital a layer of intelligence.
Much of today’s sonar analysis still happens manually, a legacy of Cold War-era infrastructure like the SOSUS (Sound Surveillance System). Acoustic data flows to small control rooms where analysts use headphones and analog screens to identify signals from vast underwater spaces. AndrenaM aims to change that through automation.
“Our vision is to secure the oceans,” said Cernosek. “We’re doing that by building a distributed sensing network a sonar mesh.”
AndrenaM’s system is a fleet of low-cost, semi-attritable smart buoys that passively listen to underwater environments. These sensors process sound signals using on-board edge computing, reducing the need for high-latency or high-bandwidth data transfers. Information is streamed via satellite to ground stations or autonomous drones, allowing real-time analysis, classification, and decision-making.
The startup’s software integrates with existing naval and commercial command systems, enabling interoperability with drones, autonomous subsurface platforms, and centralized military networks. This makes AndrenaM’s product adaptable to both government and commercial clients, from national navies to port authorities.
A key technical focus is on building a large library of acoustic signatures, which can be fused with AIS (Automatic Identification System) data to identify vessel types. In conflict scenarios where AIS might be turned off, AndrenaM hopes its models can still track vessel activity using only sound-based classification. This capability is especially relevant for areas like the South China Sea, where naval stealth and gray zone activity are escalating.
Initially, the company used off-the-shelf hydrophones for testing but plans to vertically integrate by manufacturing its own buoys. That shift would allow more control over costs, improved system performance, and faster iteration on sensor design. “A lot of our competitors are just integrators,” said Cernosek. “They take parts from everywhere, patch them together. It works, but it’s expensive and fragile. We want to build the full stack.”
The funding round came together quickly and unconventionally. After reviewing the company’s pitch, First Round partner Meka Asonye flew himself from San Francisco to Los Angeles (he’s a pilot) to meet the team over the weekend. The founders, still grinding through weekend work, agreed to a Saturday meeting. By Monday night, they had a signed term sheet.
“Oftentimes these early-stage companies are drawing things on a napkin, and they’re years and years away from being ready,” Asonye told Business Insider. “The AndrenaM team is actually deploying stuff off the coast of California, and the technology already works.”
That real-world progress is rare in defense tech, especially at the seed stage. The current eight-person team includes engineers from SpaceX, Palantir, Anduril, Saronic, Arc, and ABL Space. With the new capital, AndrenaM will double headcount to 16, focusing on software engineers and system builders. One of the first purchases? A boat. The company has already begun assembling and deploying its prototypes in open water.
Credits: AndrenaM
“If you want to be the forward-deployed engineer here and go on the boat with us and deploy these systems and train them, this is your opportunity,” said Cernosek. “You can sit in a cubicle, but do you really want to?”
The startup’s roadmap includes three stages. The first now underway is focused on pilot deployments and algorithm development. This includes refining signal processing, hardware-electronics integration, and machine learning models for classification. The second phase will scale deployments with design partners across defense and public safety. The final stage envisions a global mesh of acoustic sensors blanketing the ocean to provide persistent, autonomous maritime awareness.
The ambition is matched by a deeper motivation. Cernosek, whose family immigrated to the United States from then-communist Czechoslovakia, credits much of his drive to national service.
“This country has done very well for my family, my parents came here with $60 in their pocket,” he said. “I want to build a generational company that will have a massive impact for the United States.”
Maritime domains still suffer from a knowledge gap. Despite covering 71% of the Earth’s surface, oceans remain far less mapped and monitored than land, air, or even space. The company’s immediate focus is to double its team from eight to sixteen, primarily by hiring software engineers. It has already purchased a boat to support its hardware development and field deployments.
