The radar is about the size of a suitcase. It weighs 100 kg. The boat that carries it displaces 2.5 tonnes.
That pairing was on display at the Royal Navy's first Autonomous Squadron commissioning in Portsmouth this month. It is the service's answer to a problem that gets more expensive every quarter: small drones that fly below a warship's horizon. The drone is cheap. The ship is not.
On 10 November the Ministry of Defence confirmed a £15 million contract with Saab UK for several Sea Giraffe 1X radars. They will go onto Kraken Technology's K3 Scout uncrewed surface vessels under Project BEEHIVE. The quantity is undisclosed. So is the delivery schedule.
The number that matters is smaller than £15 million. The Royal Navy already bought 20 K3 Scouts for £12.3 million in March. This contract is the first funded step in turning those hulls into sensor nodes.
A picket line made of small boats
Sea Giraffe 1X is a 3D AESA radar on the X band. Saab lists a total system weight below 150 kg and a topside weight of 100 kg. It refreshes the full 360-degree search volume every second and is built to pick out small, slow targets while telling fixed-wing aircraft, helicopters and surface contacts apart.
Saab quotes an instrumented range of 100 km for the naval version. On a K3 Scout, the radar is not the constraint. Height is.
The horizon does the arithmetic
With the antenna less than 2 metres above the waterline, a drone at 30 metres appears on the radar horizon at roughly 28 km. Fly lower and it appears later. Wave crests can mask the antenna in a moderate sea. The shallow grazing angle is where clutter is worst.
Those numbers look modest. The design answers them with placement. A picket pushed forward of a port, a task group or an offshore energy site adds warning time for every kilometre it sits ahead of what it protects.
The K3 carries the sensor only. It passes tracks to other platforms for engagement. That makes the contract a bet on distributed sensing. It does not buy a new interceptor.
What the modular bay changes
Kraken's pitch is the payload bay. The same hull can be re-roled for surveillance, counter-drone work or strike without changing the platform, according to chief executive Mal Crease. The radar slides into a bay designed for mission payloads from the start.
The industrial numbers explain the speed. Kraken raised $175 million in July at a $1 billion valuation and is scaling toward 1,000 boats a year at a 35,000 sq ft facility in Fareham. Saab UK builds the radar on the same campus. The two companies took the prototype from concept to sea trials in under seven months.
£15M — radar contract, quantity undisclosed
100 kg — Sea Giraffe 1X topside weight
~28 km — radar horizon against a 30 m drone
20 — K3 Scouts bought in March for £12.3M
What £15 million actually buys
The contract is small next to a frigate. That is the point. A line of radar boats costs a fraction of another escort, and it can sit in places an escort should not go. The Navy's phrase is distributed sensing: move the sensor away from the ship so the ship can keep its emitters quiet.
As we wrote in November, the Navy's robot-warship maths put autonomy at sea near $40 million a hull. A radar picket is the cheaper end of that curve.
The weak link is the network. A radar picture is useful only if it reaches a shooter or a commander in time. The K3 carries the sensor. It does not close the kill chain. The data link, the track fusion and the rules for handing hostile tracks to crewed ships remain the hard parts.
Physics adds its own bill. A 2.5-tonne boat is lively in a seaway. It needs fuel, maintenance and somewhere to hide when the weather turns. An A400M airdrop trial in July showed one way to put a K3 on a distant coast. Sustained operations are a different problem.
The Royal Navy commissioned its 1st Autonomous Squadron at Portsmouth on 5 November. The radar contract landed five days later. That order is the real signal. Procurement usually follows doctrine. Here the hardware is arriving first.
What the £15 million does not buy is certainty about the drone threat. It buys time, the 28 km kind, if the boat is in the right place. Whether the Navy can keep enough of them there, networked and fuelled, is the question the next contract will answer.