Spain’s New Underwater Multirole Loitering System

Arquimea of Spain has expanded into the naval loitering munition field with the acquisition of Perseo Techworks, bringing the S-Wise underwater system into its catalogue. This new platform was recently presented at the DSEI exhibition in London after earlier appearances at defense shows in Madrid.

A Multirole Platform

Calling the S-Wise just a loitering munition would be too narrow. It is a multirole underwater vehicle capable of working in:

• Loitering munition (LM/ISR) mode – carrying a warhead for strike missions while also collecting intelligence.

• Mine countermeasure (MCM/ISR) mode – using advanced sonars to locate and track underwater threats.

Its design allows operators to swap the front section: either a 5 kg warhead (single or tandem shaped charge) or a forward-looking sonar.

Design and Build

• Length: 2.23 metres

• Diameter: 0.245 metres

• Weight: 50 kg plus more than 30 kg payload capacity

• Payload volume: over 30 litres

The body is hydrodynamically shaped, with deployable wings for maneuverability and an X-shaped rudder system at the rear. The hull is produced using additive manufacturing and acoustically transparent plastics, which reduces cost and makes it easier to repair or manufacture parts even aboard ships.

Propulsion and Endurance

The S-Wise can be fitted with either dual counter-rotating propellers for stealth or a single propeller for speed. It uses electric motors (3 kW continuous, 6 kW in boost mode) powered by Li-Ion batteries with in-house management systems.

• Top speed: over 8 knots

• Range surfaced: 85 NM at 2.75 knots

• Range submerged: 80 NM at 3 knots, or 30 NM at 5.2 knots

• Operational depth: up to 50 m with additive parts, up to 300 m with conventional housings

It can operate in sea states 4–5, with launch and recovery possible up to sea state 3–4.

Brains and Sensors

At its core, the S-Wise uses a Perseo ORA onboard computer with a dedicated GPU optimized for artificial intelligence. This supports automatic target recognition, object tracking, obstacle avoidance, and real-time mapping.

Navigation tools include an inertial measurement unit, geomagnetic device, static and dynamic pressure sensors, GNSS, and optionally a Doppler velocity log.

In MCM/ISR mode, it can carry Arc Scout MK II side-scan sonar and Ranger synthetic aperture sonar. In LM/ISR mode, additional explosive wings can be fitted, raising destructive potential.

Operations and Control

The system maintains a man-in-the-loop approach. Operators can control it via:

• WiFi, LTE/5G, or long-range links when surfaced

• Optional USBL underwater communication when submerged

The package also includes mission planning tools and a training simulator, allowing crews to rehearse missions in synthetic environments before real operations.

Why It Matters

The S-Wise is one of the first compact underwater systems that combines strike, reconnaissance, and mine countermeasure roles in a single, modular design. With its AI-based autonomy, low-cost production methods, and flexible payloads, it represents a new generation of naval unmanned systems ready for real-world deployment.