Saildrone is expanding into military applications
Saildrone’s wind-powered robotic vessels are sparking curiosity. The company recently launched the Spectre, which is no less than 52 metres long. It no longer relies solely on the wind to sail either. But what exactly do Saildrones do, and what are they capable of?
We have combined a short article in SWZ Maritime about the new headquarters of the Danish company Saildrone with a jigsaw of information published by the company itself on its website and in its own publications.
Saildrone designs, builds and operates unmanned surface vessels (USVs), with a fleet of more than seventy such vessels deployed worldwide, operating 24 hours a day, 7 days a week and 365 days a year.
4 classes
The company has four classes of USVs: the 7-metre-long Explorer, the 10-metre-long Voyager, the 20-metre-long Surveyor and the 52-metre-long Spectre. In effect, they are autonomous, long-endurance sensor platforms at sea. They can sail independently for months on end, collecting data, detecting objects and transmitting that information virtually in real time. The latest generation is also clearly geared towards military anti-submarine warfare and even armed missions.
The Explorer is essentially a very long-endurance autonomous ocean observation station. It collects meteorological and oceanographic data and, according to Saildrone, can remain operational for more than twelve months. This is of interest for applications such as weather forecasting, climate research and hurricane research.
Voyager is much more of a sentry at sea. Equipped with radar, AIS, infrared cameras and other sensors, it can detect and classify ships — including those not using their AIS transponders. It can also map the seabed. In a US Navy operation, ten Voyagers covered more than 130,000 nautical miles and recorded 116,000 unique contacts.
Surveyor is the large sensor vessel. Using multibeam sonar, it can map vast areas of the seabed; for example, it has been used for cable route surveys and deep-sea mapping to depths of 5,500 metres. At the same time, it can carry radar, electro-optical/IR sensors, AIS and other military sensors.
And then there is Spectre, announced in April 2026. This changes the picture considerably. The 52-metre-long vessel is designed for a maximum speed of around 30 knots and is specifically intended for anti-submarine warfare (ASW), ISR and strike missions. There are two variants: a very quiet, long-endurance version and a faster, stealth-oriented version.
What makes them so interesting?
What makes them special is not just the sensors, but the combination of autonomy, endurance and low cost.
A manned patrol aircraft, frigate or submarine must constantly return to base for crew, fuel, maintenance and rest. A Saildrone, on the other hand, can remain at sea for months. The vessels combine wind, solar power and — in the larger models — efficient engines. This means, for example, that ten or dozens of autonomous vessels can be deployed across a vast maritime area as a sort of network of mobile sensors.
The software can also integrate radar, cameras and AIS data. A system might, for example, identify:“There is a vessel there; it is not transmitting an AIS identification; its course is deviating; the camera confirms a specific type of vessel.” That sort of information can then be sent to a command centre, where people decide what action to take.
And what else can they do?
There are at least five major areas of development:
Detecting submarines
This is probably one of the most important developments. An USV can carry acoustic sensors and towed sonar arrays, enabling it to listen for underwater sounds over long periods. The aim is not only to spot surface vessels, but also to detect, track and classify submarines.
This is particularly valuable from a military perspective: you can deploy dozens of relatively inexpensive autonomous listening posts around a strategic strait or submarine route, rather than having a manned frigate or aircraft constantly patrolling the area.
Monitoring of cables, pipelines and other subsea infrastructure
Using sonar and sub-bottom profilers, they can not only view the seabed but also investigate structures and layers beneath it. In 2026, for example, Saildrone deployed a Voyager to investigate critical infrastructure in the Baltic Sea.
In theory, such systems could therefore form a kind of permanent alarm system for subsea infrastructure.
An autonomous maritime ‘radar network’
Imagine a coastal area with dozens of USVs, equipped with radar (active detection). AIS (for identification), cameras – including infrared (for tracking contacts) – acoustic sensors and AI for interpreting specific behaviour; this provides a vast amount of information, combined into a single operational picture.
That is far more than just a collection of drones. It becomes a distributed sensor network at sea. Saildrone itself already describes fleet-based surveillance in which multiple vehicles can cover thousands of square nautical miles.
Much more autonomous oceanography
On the civilian side, the potential is at least as great. The same platforms can, for example:
- measure climate change;
- track storms and hurricanes;
- study fish stocks and ecosystems;
- measure ocean currents;
- produce new nautical charts;
- investigating cable routes;
- studying volcanic and geological activity;
- collecting data over many years in places where research vessels rarely go.
For example, the Surveyor has already autonomously mapped thousands of square kilometres of seabed.
Ultimately: autonomous military applications
This is the most significant step. Saildrone no longer positions the new Spectre solely as a sensor platform. This shifts the concept from: “I’m sending a robot out to sea to look” to : “I’m sending an autonomous robot out to sea that can look, listen and track for months on end, and ultimately carry out certain military functions.” Thatis a fundamentally different category.
A natural evolution
Saildrone has long since ceased to be primarily a company that makes unmanned sailing boats. The more interesting story is that they are attempting to build a kind of autonomous infrastructure layer for the ocean. This development can be represented in a sort of flowchart as follows: measure → detect → recognise → track → predict → collaborate → observe underwater → and ultimately carry out actions.
And it is precisely this transition from ‘sensor’ to ‘autonomous maritime operator’ that makes the Spectre and the larger Surveyor platforms of interest to the European defence industry. Saildrone’s activities in the Baltic Sea, where Russian hybrid warfare directed towards Europe is currently at its most intense, demonstrate this. Furthermore, Saildrone’s recent European expansion shows that this is no longer a purely experimental project: last month, the company announced production plans in the Netherlands, Norway and Poland.
For instance, the first 52-metre Saildrone Spectre to be built in Europe will be constructed at the Van Der Valk shipyard in the Netherlands. The expansion also includes the official opening of Saildrone’s EU headquarters in Copenhagen. In addition to the project in the Netherlands, there are two further separate European construction contracts in Norway and Poland.
The new office in Copenhagen and the planned production in the Netherlands, Norway and Poland will provide a local European infrastructure to meet the strong demand for products and enable the company to rapidly build, deploy and maintain USVs in all European waters.
Source: an article by Mariska Buitendijk in SWZ Maritime, supplemented by our own research. All factual information is sourced from Saildrone.
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