The companies building the instruments of the deep sea

The most reliable way to work out what is happening in ocean technology is to ignore the promotional material about mapping the unmapped and read the order books instead. When you do, the same two words appear in company after company: defence, and offshore.

Kongsberg Gruppen’s results for the fourth quarter of 2025, published on 6 February 2026, report full-year operating revenues of NOK 5,130 million for its Kongsberg Discovery business, 16% up on 2024. Fourth-quarter revenues were NOK 1,442 million against order intake of NOK 1,759 million, a book-to-bill ratio of 1.22 for the quarter, with order intake in the same quarter of 2024 at NOK 1,300 million. The company describes Discovery as strongly positioned in seabed mapping and the sustainable management of ocean resources, while also gaining increasing exposure to defence and security markets, and lists the demand it expects to continue: offshore energy production, commercial fisheries, climate and environmental monitoring, and the protection of critical infrastructure.

That last item was not on the list five years ago. It is now doing a great deal of the work.

A book-to-bill ratio above one is the least glamorous and most informative number in that release. It means Discovery signed more new orders in the quarter than it delivered in it, so the backlog grew. Read the period carefully, because this is where the ratio is most often mishandled. Kongsberg publishes it for the quarter, and no full-year equivalent for Discovery appears in the release, so a single strong quarter is what the 1.22 describes. Even so, for a supplier of long-lead instrumentation it is the closest thing available to a forward statement about demand, and it is harder to dress up than a growth percentage.

Why the buyer changed

On 22 January 2025 the Defence Secretary told the House of Commons that the Russian vessel Yantar, described as a spy ship used for gathering intelligence and mapping the UK’s critical underwater infrastructure, had entered the UK exclusive economic zone about 45 nautical miles off the British coast. The response involved RAF maritime patrol aircraft, two Royal Navy ships, and RFA Proteus, the multi-role ocean surveillance ship the statement credits with an indispensable role in safeguarding offshore infrastructure.

Every cable, pipeline and interconnector that a state adversary might be surveying is a thing somebody else has to survey, monitor and repair. That produces demand for exactly the same instruments the offshore energy industry buys: multibeam sonar, autonomous underwater vehicles, subsea positioning, and a vessel that can stay on station without costing a crew.

The companies below are the ones with enough public disclosure to say something checkable about. That is a selection criterion, not a ranking of quality, and it excludes some good firms.

Fugro

The Dutch geo-data company is the clearest case of the crewing shift becoming a business model. Its full-year 2025 results, published on 27 February 2026, report revenue of EUR 1,848.1 million and EBIT of EUR 90.9 million, with the chief executive listing an increased fleet of uncrewed surface vessels among the initiatives meant to accelerate remote operations.

The regulatory milestone underneath that is more interesting than the revenue line. On 25 January 2024 Fugro announced that its Blue Essence vessel Fugro Vaquita had received Category 0 approval from the UK Maritime and Coastguard Agency, which the company describes as the highest level of approval for autonomous vessels and which made it the largest uncrewed surface vessel able to operate fully remotely with unrestricted access.

An approval is a harder fact than a demonstration. It means a national maritime authority has accepted a class of vessel operating without people aboard, in unrestricted waters, which is the permission that turns a technology demonstration into a fleet plan.

Ocean Infinity

The British firm has spent five years converting the same idea into steel. On 15 December 2025 it announced delivery of the final vessel in its Armada fleet, completing a fourteen-vessel programme begun in 2020, of which twelve were then in live operation. The fleet runs in two classes, 78 metres introduced in 2023 and 86 metres following it, described by the company as lean-crewed, smaller than conventional equivalents, and integrated into an onshore control centre for live monitoring and remote control.

Ocean Infinity is also the firm behind the most expensive negative result in the sector. Its statement on the conclusion of the search for MH370 records that it left the Indian Ocean search area on 23 January 2026, having mapped more than 140,000 square kilometres of seafloor across expeditions totalling over 150 days at sea since 2018, without finding the aircraft. The chief executive’s framing is worth quoting because it is unusually honest for a company statement: the value delivered is that the aircraft is not where they looked.

What Ocean Infinity does not publish, because it is private, is revenue, utilisation or day rates. A fourteen-vessel newbuild programme is a large amount of capital and there is no public document from which an outsider can work out what it earns.

Exail Technologies

The French group is the sector’s clearest evidence that the money moved to defence. Its 2025 annual results, published on 18 March 2026, report EBITDA of €103 million, up 40%, revenue growth of 28%, and order intake of €844 million, up 87%.

The milestone the company leads with is the delivery to the Belgian and Dutch navies of a first operational mine countermeasures capability, which it describes as the world’s first fully integrated autonomous naval drone system capable of carrying out an entire demining mission autonomously and safely. Mine countermeasures is the purest expression of the argument for removing people from the water, and it is the application that has pulled subsea autonomy from pilot into programme of record.

Teledyne Marine

Include this one for a different reason: it shows how little a very large supplier is obliged to tell you.

Teledyne’s marine instrumentation businesses sit inside its Instrumentation segment, alongside environmental and test and measurement products. In the third quarter 2025 earnings release of 22 October 2025, that segment reported net sales of $363.6 million. The only marine number in the document is a $5.3 million increase in sales of marine instrumentation, attributed primarily to stronger offshore energy and defence markets.

So the direction is confirmed and the magnitude is not disclosed. Anyone quoting a revenue figure for Teledyne Marine as a business has constructed it, because the company does not report one.

SEA-KIT International

The Essex firm’s claim rests on a competition rather than a filing, but it is a competition with published rules and independent judging, which makes it a stronger fact than most.

The Shell Ocean Discovery XPRIZE was won by the GEBCO-NF Alumni team, taking a $4 million grand prize, using what the foundation describes as a robust and low-cost unmanned surface vessel, the SEA-KIT, together with a cloud-based data processing system. The technical bar was specific: map at least 250 square kilometres of seafloor at five metres of horizontal resolution or better, within a 24-hour field test.

That is the design brief the whole uncrewed survey sector now works to. Resolution, area and time, with nobody on the boat.

The economics are about berths, not sensors

Read the six entries above together and the common engineering project is not better sonar. It is removing people from the water.

That is worth spelling out because it explains why the sector’s investment has gone where it has. The cost of an offshore survey is dominated by the vessel, and the cost of the vessel is dominated by the fact that it carries people. Berths set the hull size. Hull size sets the fuel burn, the propulsion plant and the day rate. People set the catering, the safety case, the lifesaving appliances, the medical provision and the helicopter or launch movements for crew change. A twelve-berth requirement and a two-berth requirement produce different ships, not the same ship with fewer bunks.

Take the crew off entirely and every one of those constraints relaxes at once. That is why Ocean Infinity built 78 and 86 metre hulls designed around an onshore control room rather than converting existing survey vessels, and why Fugro’s regulatory milestone was about operating without restriction rather than about sensor performance. The instruments were already good enough. The permission and the hull were not.

The second-order effect is on who can compete. An onshore control centre is a fixed cost that gets cheaper per vessel as the fleet grows, which favours operators with many hulls and disadvantages the single-vessel contractor that used to win regional work. Expect consolidation, and expect it to be reported as a technology story when it is really a utilisation story.

What is not public, and it is most of it

Ocean technology is dominated by private companies, and in Britain that means Companies House rather than a stock exchange.

Take Sonardyne, the British subsea acoustics manufacturer, as the example. The register at Companies House shows Covelya Group Limited, company number 12493148, a company previously registered under the name Sonardyne Group Limited, filing group accounts for successive years, most recently made up to 31 December 2025.

Group accounts filed at Companies House are a real disclosure and they are also the floor. They are prepared to a statutory format that has nothing to say about which products sold, in what volumes, to which navies. Anyone wanting that has to ask the company, and the company is under no obligation to answer.

The consequence is that any market-sizing figure for subsea instrumentation, and there are several in circulation, has been assembled from the same partial public record plus a set of assumptions the author has not shown you. This desk does not reprint them.

What can be said with confidence is narrow and useful. Two listed suppliers reported double-digit growth in 2025 and both named defence as a driver. One maritime regulator has approved an uncrewed vessel for unrestricted remote operation. One British operator has completed a fourteen-hull uncrewed fleet. And a British government minister has told Parliament that a foreign vessel was mapping the cables the country runs on. Those four facts are enough to explain the order books without inventing a market size.

The security dimension of that story is followed in more detail under cybersecurity, and the rest of this desk’s work on industries that stopped being emerging without becoming ordinary sits in emerging technology.