Seeing the Seabed with Ulysses

Ulysses first built a robot to replant seagrass. Now it’s being offered to the US Navy to hunt sea mines, so that divers don't have to.

It's more or less the same machine: a modular autonomous submarine, cheap by the standards of the business, sent down to do patient, dangerous, repetitive work in a place most people would rather not go.

The company's vision is an insight into a larger shift.

The economics that put swarms of cheap drones over Ukraine are now heading under water, and a two-year-old startup founded by three Irishmen and a Scot is betting it can get there first.

Almost everything the modern economy runs on crosses the ocean. Roughly 80 percent of world trade by volume moves by sea, much of it funneled through a few narrow choke-points.

About a fifth of the world's oil passes through the Strait of Hormuz, some 20 million barrels a day. 

The Strait of Malacca, the busiest on Earth, carries close to a third of seaborne crude. 

Suez, Bab-el-Mandeb, the Panama Canal: the map of global commerce keeps narrowing to a few miles of water. And those choke-points have spent two years proving how fragile they are. 

Houthi missiles and drones cut Red Sea traffic by roughly 70 percent at the peak, forcing ships the long way around Africa and dragging Suez's share of global shipping from about 12 percent to below 9; a record drought cut Panama Canal transits by a third. 

The sea is not a stable backdrop to world affairs. It’ a contested, brittle system, and those disruptions at least happened on the surface, where they could be seen. The most exposed layer is hidden from view. 

The seabed is critical infrastructure, and almost no one is watching. Roughly 99 percent of the world's internet traffic runs through cables on the ocean floor, alongside the fuel pipes and power lines that keep the global economy ticking. 

For a maritime nation like the UK, more than nine-tenths of communications pass under the sea. It is, in any practical sense, unguarded.

And the vulnerability is no longer hypothetical. Since the Nord Stream explosions of 2022, the seabed has become an active grey-zone battleground. 

Russia's shadow fleet has been linked to damaging at least eleven cables in the Baltic since late 2023; in a few weeks at the end of 2024, three cables between five NATO allies went dark. A year later Finnish special forces were boarding suspected anchor-draggers. 

Nor is it only Europe. Taiwan's cables were cut five times in 2025, and China has unveiled a deep-sea device that can sever the most heavily armored lines at 4,000 metres. 

NATO says Russia is actively mapping allied infrastructure on the ocean floor; the EU has committed €347 million to protecting subsea cables, its largest such investment yet.

And yet the sea resists being watched. There is no GPS underwater; radio signals die within metres; pressure and salt destroy hardware; and the legacy tools — crewed survey ships and divers — are too few, too slow, and too costly to be everywhere they’re needed.

The strategic gap in the maritime domain isn't a shortage of weapons. It's that we largely cannot see what is happening beneath the surface. Persistent, affordable visibility of the seabed has simply never existed.

Ulysses exists to close that gap.

The idea was sketched, its founders say, on a 2023 surf trip off the west coast of Scotland. 

Four young engineers, three Irish and one Scottish, who decided the ocean was both under-protected and under-restored, and that one technology could address both. 

They incorporated in San Francisco and, trading as "The Ocean Company," first surfaced as a seagrass-restoration outfit: robots to replant the meadows that store carbon and shelter fisheries.

The later move into infrastructure inspection and maritime security looks like mission drift but is better understood as strategy. Conservation and marine science organizations supply early revenue, permits, and real hours in the water while the slow, secretive machinery of defense procurement matures. The vehicle proving itself on a reef this year is the one pitched for contested water next. 

Dual-use here isn't idealism bolted onto a defense company; it's the go-to-market plan.

The money has followed. Ulysses raised about $46 million in a small seed round led by Pebblebed, then a $38 million Series A led by Andreessen Horowitz's American Dynamism fund in early 2026, plus a strategic investment from Booz Allen Hamilton. 

Disclosed revenue is still modest, just north of $5 million, from partners including the US Navy and the Australian government. This is an early-stage company, and an honest profile has to keep that in view.

Ulysses builds a family of machines rather than a single hero product. 

Mako, is the autonomous underwater vehicle, whose distinguishing feature is modularity: allowing operators ‘to swap modules and payloads like Lego’. 

The company says it can be pulled apart and reconfigured for a new mission in minutes, with a “universal connector" that takes almost any sensor or robotic payload. 

It carries enough onboard compute to make its own decisions, a necessity underwater, where nothing can be piloted in real time.

Leviathan, due later this year, is the heavy-lift workhorse: a subsea vehicle for physical work rather than pure sensing, able to hold position and manipulate payloads up to around 250 pounds with the fine, six-degree-of-freedom control needed to repair infrastructure, not just photograph it.

Tying the fleet together is Kraken, an autonomous launch, recovery, and recharge system that deploys, retrieves and recharges vehicles with no human — and no crewed ship — in the loop. 

In a business where persistence usually means paying for a crewed vessel around the clock, that’s what lets a handful of vehicles become a fleet that can stay deployed permanently.

One caveat: nearly all of this rests on the company's own claims. Mako is still ramping toward production and independent verification is thin. 

The headline claims — "50 times cheaper" than legacy providers, "40 times" the subsea compute, as low as $50,000 a unit — are statements of ambition, not established fact. 

As such, they describe the bet rather than the track record.

Ulysses isn't swimming alone. Maritime autonomy is sorting into camps that are getting more and more crowded.

Saildrone runs ultra-endurance surface craft for surveillance; Saronic builds fast uncrewed attack boats; Anduril is building heavyweight undersea strike vehicles. 

All are larger and better capitalized than Ulysses; against them, a $46 million startup is a minnow. 

Its wager is that the giants are optimizing for the wrong layer — big, exquisite, mostly surface platforms — while the opening is a swarm of small, cheap, modular vehicles working below the surface, plus the launch system that keeps them there. 

Ulysses' bet only works if someone will pay for cheap, persistent eyes on the ocean floor. And it seems they will.

Major military budgets now treat undersea autonomy as a category worth funding. 

The Pentagon's 2026 budget gave autonomy its own $13.4 billion line, with $734 million earmarked for underwater systems and the account for large undersea drones leaping from under $10 million to roughly $185 million in a year. 

Australia has signed a A$1.7 billion program for extra-large robotic submarines, NATO is fielding uncrewed fleets in the Baltic to watch its cables, and Britain runs a dedicated seabed-warfare ship. 

The customer base Ulysses is selling into is discerning, but it has deeper pockets than ever.

Private capital has read the signal from military buyers, and is deploying its own capital even faster. 

By various counts, defense-tech venture funding hit a record in 2025, on the order of $50 billion, and maritime is repeatedly named the next frontier. 

Saronic has reached a $9 billion valuation. Helsing, Europe's most valuable defense tech company, dived underwater with a fleet of sensing gliders. Purpose-built funds — from the €1 billion NATO Innovation Fund to the Pentagon-seeded Mare Liberum — now exist to push money into maritime tech. The valuations are frothy, and some of this won't survive contact with reality, but the direction is unmistakable.

Against that backdrop, the money behind Ulysses stops looking like a curiosity. a16z backed it on the thesis that "the next wars will be fought over oceans", and Booz Allen took a strategic stake, betting that seabed awareness is where budgets are heading. 

Indeed, this may be a hint that Ulysses' likeliest future is as a component inside someone else's program rather than a standalone prime. 

A venture firm is always talking its book; what makes this one credible is that the budgets it's betting on are now actually being written.

The domain is real, and Ulysses seems to have read it correctly. In the air the contest became one of cost and mass; under the sea the binding constraint sits a step earlier, at visibility itself. 

Whoever makes the seabed persistently, affordably visible will set the terms for both defending and contesting it. Ulysses is aimed squarely at that.

What it hasn't done is the hard part. Hardware that is both cheap and able to survive the most hostile environment on Earth is exactly what the industry finds difficult; low-cost production and ocean-grade reliability are often at odds. 

The dual-use positioning that opens doors today may, at scale, force a choice between two very different customers. 

And the same rush of public and private money placing the bet on Ulysses is arming the giants they’ll need to contend with. Anduril, Saronic, and Helsing, not to mention the traditional primes, are better capitalized and moving into the same water.

Where does that leave this promising young start-up? 

Ulysses is one of the clearest, earliest, and most promising bets that a small team can industrialize the visibility, management, and defense of the ocean floor through affordable, autonomous, and modular technology. 

Whether it's the company that actually does so is a question that will be answered in how they navigate the treacherous waters ahead.