A Singapore based designer and manufacturer of unmanned surface vessels (USVs) said one of its vehicles was recently deployed for more than three weeks in the South China Sea.

The 22-day continuous deployment marks the longest ever for Zycraft’s wholly developed Vigilant class 17-meter independent unmanned surface vessel (IUSV), which traveled a total distance of 1,900 nautical miles South China Sea.

Command and control of the IUSV was done using satellite communications from Singapore at Zycraft’s command center. The IUSV was run on autopilot mode and carried out autonomous vessel and obstacle avoidance using its proprietary software and making use of information from day and night cameras, radar and automated identification system (AIS).

Moving at a speed of 5 knots with occasional bursts of high speed transits, the vessel sailed with just over 6,000 liters of diesel and returned to its Singapore home port with 2,800 liters remaining.

The endurance test validated the fuel efficiency of the vessel which is built using Arovex, giving it a hull that is strong but lightweight. Powered by twin Yanmar 480-horsepower marine diesel engines, the test also validated the robustness of the vessel’s mechanical and electronic systems.

“This endurance test is a major capability demonstration of the IUSV,” said James Soon, president of Zycraft. “It showed that the IUSV can be effectively deployed for surface surveillance tasks for extended periods at sea. Over the 22 day period, we not only learnt important lessons about USV operations, but were also amazed at the knowledge gained in shipping patterns and traffic in the area that can only be realized by a 24/7 presence. Clearly, this test also confirms that when properly equipped with underwater sensors, the IUSV can also be very effective in underwater survey and surveillance work.

Soon added, “Our Vigilant IUSV is currently the only USV equipped with a Seakeeper stabilization system and this is essential during periods of rough seas for effective sensor performance.”

“We were also able to effectively update software to the IUSV in real time based on observations to further improve performances. This validates the flexibility of the Vigilant IUSV software design,” Soon said.