VESSEL REVIEW | Nigerian survey company acquires hybrid long-endurance USV

Compass Survey, a hydrographic survey company operating out of Port Harcourt in Nigeria, has taken delivery of a new unmanned surface vehicle (USV) from Hong Kong-based maritime robotics specialist OceanAlpha.

Engineered to streamline workflow integration, the 8.4-metre (28-foot) aluminium catamaran USV supports standard survey instruments including a multibeam echosounder, a towed side-scan sonar, a towed magnetometer, a sub-bottom profiler, and USBL positioning systems.

The onboard wet-end payload lifters and towing system will permit quick configuration changes between hydrographic mapping, pipeline inspections, and scientific research missions.

“Its core advantages are reflected in mature key technologies, including the power system, high-redundancy design, and a comprehensive suite of deck machinery — all of which have been validated through multiple collaborative projects and successfully passed acceptance testing,” OceanAlpha told Baird Maritime.

"Launched in 2025 as OceanAlpha's flagship marine survey USV, this platform reflects the company's latest advances in design and operational capability. OceanAlpha has strong confidence in the craft's potential to advance the marine USV sector, driven by its versatile performance and proven engineering."

The hybrid propulsion system will enable the craft to sail up to 1,500 kilometres (930 miles), or stay out at sea for up to eight days at four knots, significantly reducing the need for frequent vessel retrieval during large-scale surveys.

Enhanced stability from four redundant electric outboard motors and two 20kW diesel generators will enable deployment under a range of conditions in coastal waters as well as open-ocean environments.

The vessel features exceptional control and flexibility under various operating conditions, with capabilities such as differential steering, on-the-spot turning, and reverse thrust.

OceanAlpha has also independently developed key components such as a ruggedised main controller, an energy management module, and a propulsion control system. The company said technologies have been deployed in over 300 unmanned platforms across fields including environmental monitoring, marine surveying, and security protection, ensuring reliable and stable operation.

Durable multi-role platform

The builder said the USV is the first customised craft of its kind introduced in Nigeria.

“The owner had very specific and rigorous expectations for this unmanned vessel, requiring a highly adaptable platform capable of handling diverse marine survey missions. The vessel needed to be compact yet robust, with precise control for low-speed survey work, endurance for long-range missions, and the ability to operate safely in sea state three.”

OceanAlpha said the USV also had to support both remote and autonomous operations, with reliable payload deployment, real-time data transmission, and stable navigation, including station-keeping and path-following. Communication reliability was also deemed essential, with redundant systems for uninterrupted shore connectivity.

“The platform required modular equipment interfaces to accommodate various sensors, enabling operations in different marine environments, from coastal areas to offshore sites,” added OceanAlpha.

The builder said the USV addresses critical challenges in marine survey operations by combining long endurance with operational flexibility. This capability reduces reliance on motherships, enabling extended offshore missions that were previously deemed to be logistically complex or costly.

The USV is designed for daily duties focusing on underwater surveying and mapping tasks including pipeline route investigation, subsea pipeline depth measurement, and subsea pipeline scouring detection.

“Depending on mission needs, it can be equipped with various detection equipment via modular interfaces,” the builder told Baird Maritime. “Routine operations include autonomous navigation along pre-planned routes, real-time transmission of data to shore stations, and remote control of payload deployment/recovery. It also performs self-health monitoring, issuing alerts for abnormal conditions like equipment faults or low power.”

The propulsion has been configured to allow charging of the onboard lithium batteries via the generator. Steering is controlled by differential thrust, and reversing is achieved by reversing the thrusters. All these functions are managed by a dedicated propulsion control algorithm.

The two hydraulic lifters are installed in moonpools and are exclusively for use with underwater acoustic equipment. These mechanisms raise equipment out of the water during non-operation to reduce drag and protect sensors. The lifters feature detachable crossover flange structures, allowing quick adaptation to different underwater acoustic equipment and enhancing payload flexibility.

“Both the lifters and towing system are remotely operable, with position sensors feeding real-time status data to the control system—enabling fully unmanned payload deployment and recovery, a key advantage for safety and efficiency,” said OceanAlpha.

A stern-mounted towing system comprises an automatic winch and hydraulic towing gantry, while the other key equipment on the deck includes GNSS antennas, electro-optical pods, searchlights, an auto-folding antenna mechanism, navigation lights, bollards, fenders, and a 500mm by 600mm top moonpool for auxiliary payload deployment.

“You rarely see side-scan towing systems specifically designed for USVs in this industry. Our fully self-developed towing system can autonomously deploy and recover the most common side-scan sonars on the market, significantly enhancing the operational performance of USVs. The towing system’s use of SUS316 stainless steel for underwater components ensures corrosion resistance in high-salt environments, extending service life.”

The design work entailed overcoming a number of challenges, as OceanAlpha explained.

“Traditional survey methods struggled with efficiency, environmental impact, and adaptability in complex marine operations.​​ To solve these challenges and advance maritime surveying, OceanAlpha partnered with the client to develop innovative solutions.”

Compact, segmented hull allowing for ease of reconfiguration and maintenance

To ensure system Integration and safety, the USV needed to be divided into five isolated sections – forward cabin, electronics, generators, batteries, and deck machinery – to ensure independent operation, ease of maintenance, and equipment replacement without interference.

Coordinating diesel generators, electric thrusters, and multiple networks also became necessary, as it aided in the reliable management of energy and data transmission for long-term missions.

The USV also needed to be of modular construction for greater flexibility. To that end, OceanAlpha designed standardised payload interfaces (i.e., "plug-and-play" mounts) to enable quick equipment swaps across diverse survey tasks without the need for structural changes.

The company said that another major challenge became evident in working to achieve a reliable modular installation of deck machinery and payload systems.

“The hydraulic lifters (for underwater equipment deployment) and the towing system (for the side-scan sonar) required precise alignment to enable quick deployment/recovery, with detachable flanges and corrosion-resistant materials (SUS316L) to withstand high-salt marine environments.”

Environmental adaptability also posed challenges for the builder. Components like generators, batteries, and communication equipment needed robust waterproofing (IP65/IP67 protection) and temperature resistance (-40 to 60 degrees Celsius) to be able to operate in harsh conditions.

Ensuring the watertight integrity of the cable entries and the hatch covers as well as debugging windows became critical to preventing water ingress during navigation at high speeds or in rough seas, according the builder.

“Supply chain coordination for specialised components—such as high-performance electric thrusters, marine-grade air conditioners, and precision navigation sensors—required careful planning to ensure timely delivery and compatibility, as many parts required specialized marine certification,” OceanAlpha told Baird Maritime.

OceanAlpha is offering examples of the craft as part of a partnership program with potential customers. The program also covers training and technical guidance among others.

"This collaborative approach is designed to help partners quickly establish a presence in their regional markets, accelerate technology adoption, and jointly advance the industrialisation of USV systems."