Uncrewed at Sea: Designing a Search & Rescue Fast Interceptor

2026-08-25Higher Solutions Defense Systems Group

The second study in this series moves the same autonomy question to the water. A 14.2-meter waterjet interceptor is small enough to be launched from a pier or a mother ship, and fast enough to close a distress position before a rotary-wing asset can be spun up.

Hull and propulsion

The deep-V hull carries a sharp deadrise aft to keep the ride survivable at 50-plus knots in a short sea, with spray rails that keep the mast optics clear of water. Twin diesel waterjets remove exposed running gear, critical when the boat is expected to work in debris fields, shallow surf and alongside people in the water.

Range is the design tension. A 1,200-liter fuel load buys roughly 350 nautical miles at cruise, which sets the practical radius of action for an independent search leg before a refuel or a hand-off.

Recovery is the mission, not an accessory

The stern recovery ramp is the reason the aft third of the general arrangement looks the way it does. Recovering an unconscious casualty over a freeboard is slow and injures rescuers; a low transom ramp with a powered lift lets two crew bring a person aboard in seconds and start care on a flat deck.

Deck space forward of the ramp is deliberately unfurnished. Six survivors, a litter, or a stretcher-and-medic pairing all have to fit without reconfiguration.

Finding people: EO/IR, radar and SARSAT

The mast integrates a stabilized FLIR/EO ball for thermal detection of a head in the water at night, a small-target surface radar tuned for returns from liferafts, and VHF/UHF direction finding for 121.5 MHz homing after a 406 MHz COSPAS-SARSAT alert has cued the search area.

Cueing from space, searching from the surface, and confirming with thermal is the same layered detect-identify-act chain used on the land platform in Part I, only the failure mode differs. At sea, the clock is hypothermia.

The uncrewed option

The same hull accepts an uncrewed surface vehicle fit: the helm becomes a control station, and the boat runs autonomous search patterns over a designated box, streaming EO/IR video back over line-of-sight mesh or SATCOM. Crewed boats then get vectored to confirmed contacts instead of burning fuel on empty water.

This is where autonomy earns its place in rescue work. Machines do the search grid; people do the recovery.

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