Zelim Guardian unmanned recovery vessel
- Model
- AJ 285 + BUKH 400 hp
- Length
- 8.4 m
- Speed
- Top speed 30+ kn
- Range
- Not listed on the manufacturer's case page
Two brands represented by Hallmark Marine, working together on one vessel
Authorized Alamarin-Jet distributor in Taiwan
Propulsion for Unmanned Surface Vehicles (USVs)
Alamarin-Jet waterjets and Sigma/ACU control systems provide an integration-ready basis for propulsion and control; Hallmark Marine helps evaluate waterjet, BUKH engine and control configurations.
Why waterjets
Why USVs often use waterjet propulsion
Below are the general characteristics of waterjet propulsion, with their limitations, to assist your evaluation.
No exposed propeller
Reduces the risk of people and marine life coming into direct contact with blades; suited to rescue and nearshore work.
Note: The intake can still ingest debris, so a USV needs a way to clear it.Shallow draft, few underwater protrusions
Favours shallow-water and nearshore operation and lowers the risk of the propulsion system striking obstacles.
Note: Actual minimum water depth depends on the hull, load and intake conditions.Manoeuvrability and crash stops
The steering nozzle controls direction and the reversing bucket redirects the jet stream to produce reverse thrust, giving quick response in docking, turning and braking without reversing the engine.
Note: Stopping distance must be measured for the actual boat weight, speed and sea state.Electronic control integration
Depending on model and configuration, the steering nozzle and reversing bucket can be electrically or hydraulically actuated, with a controller accepting electronic commands.
Note: Autonomous navigation and collision avoidance are handled by the external autonomy system.Efficiency at high speed
Low underwater appendage drag at high speed.
Note: For long periods of low-speed cruising, a waterjet is not necessarily more fuel-efficient than a propeller; evaluate over the whole mission profile.Alamarin-Jet for USVs
What Alamarin-Jet offers
USV-ready interface
The EXIF interface of the Sigma Control System provides a CAN bus jet-control interface, including engine management, for commands from third-party autonomy systems.
Control integration on small USVs
AJ 160 and AJ 180/185 come standard with the ACU controller, which accepts an external analogue signal (typically 0–5 V) or NMEA 2000 CAN rudder messages; each ACU controls one actuator.
Redundancy
In the Sigma Control System, each jet is an individual bus node, and twin installations use two electrically separated primary bus lines.
External autopilot support
Sigma provides an interface for third-party autopilots; the optional Intelligent Dynamics package offers heading hold, course and track modes (track mode requires an external navigation planner).
Global experience
In February 2025, according to the manufacturer, Alamarin-Jet had supplied propulsion and control systems for more than 100 USVs worldwide over the previous year, used in defence, underwater research and search and rescue.
Integration
Control integration overview
Sigma/EXIF or ACU is evaluated according to actuator configuration, control functions and external interface requirements; signal and system integration conditions are confirmed for each project.
- Autonomous control system → EXIF external interface (CAN bus) → Sigma Control systems → Steering nozzle, reversing bucket and engine throttle control
- External autopilot → Sigma external autopilot interface → Sigma Control systems
- Controller analogue (typically 0–5 V) or NMEA 2000 rudder signal → ACU controller(one actuator per unit) → reversing bucket or steering nozzle; standard on AJ 160 and AJ 180/185
References
Manufacturer reference
Speeds and ranges are the figures published for each vessel; full test conditions were not provided.
SXX3 USV
- Model
- AJ 160
- Length
- 3.0 m
- Speed
- Top speed 35 kn
- Range
- 250 nm
Arrow 600 multirole USV
- Model
- AJ 185
- Length
- 6.0 m
- Speed
- 15 kn cruise, 35 kn top
- Range
- 200 nm
Models
Suitable models
Published case studies cover USVs of 3–8.4 m; for larger vessels, the AJ 340 and Omega series can be evaluated.
Hallmark Marine
Integration review by Hallmark Marine
Hallmark Marine can help evaluate waterjet, BUKH engine and control configurations for your hull, speed, payload and mission. Actual functions and performance are confirmed through project design and testing. We support propulsion and control integration reviews for rescue, research and inspection USV projects, and for lawful, compliant defence USV projects; supply and technical support are confirmed case by case according to product specifications, end user, end use and applicable export and import regulations.