These USVs are called the MARSEC and, as their name suggests, the small fleet performs maritime security. Since 2023, the Republic of Singapore Navy (RSN) has been operating these 30-tonne vessels with two crew aboard. However, they are now being used in a fully unmanned mode.
Singapore’s Ministry of Defence (MINDEF) stated,
“After a series of rigorous tests, the RSN’s Maritime Security unmanned surface vessels have begun operational patrols since January 2025, operating alongside manned ships such as the RSN’s Littoral Mission Vessels to enhance the security of Singapore’s waters.”
MINDEF noted that the 16.9m-long USVs add another layer of surveillance and operational response. “They conduct patrols, and when required, will investigate and interdict suspicious vessels. Operating alongside other manned vessels, the USVs will enhance the RSN’s ability to monitor and respond to situations at sea.”
Colonel Thung Yee Meng, commander of the RSN’s Sixth Flotilla, said the USVs are maintaining a naval presence, conducting escorts and investigating maritime threats. His unit is evaluating the ideal balance between manned and unmanned vessels, including factors such as manpower requirements. These USVs are now being operated by two crew on shore.
Thung added that the navy has been fine-tuning operations with the USV and assessing its interactions with other vessels. “It goes beyond remote control and incorporates several autonomous functions in how it navigates and keeps clear of hazards in conducting its missions.”
Indeed, a critical autonomous system aboard the MARSEC is an indigenous Collision Detection and Collision Avoidance (CDCA) navigation system. It allows the boats to negotiate heavy traffic in the Singapore Strait and deal with quickly changing environmental conditions.
The CDCA’s algorithms integrate data from the USV’s perception and navigation sensors (for example, its radar, automatic identification system and differential GPS), plus collision detection equipment. MINDEF stated, “This rules-based system automates the collision-avoidance decision-making process while ensuring that the USVs exhibit avoidance behaviour that complies with the Convention on the International Regulations for Preventing Collisions at Sea.”
To achieve best practices, Singapore agencies consulted with foreign organisations like the Direction générale de l’armement (DGA) in France, the US Chief Digital and Artificial Intelligence Office, and Maritime Research Institute Netherlands.
Singapore has thoroughly verified and validated the CDCA algorithm in both simulated-based testing and sea trials. MINDEF said it successfully completed more than 12 million kilometres of simulated distance without a single collision, the equivalent of 26 years of real-world testing. Additionally, the MARSEC fleet has accumulated 1,000+ hours of autonomous operations at sea without any crew intervention required.
More than 1,000 commercial vessels ply the Singapore Strait daily, and the operationalisation of these unmanned vessels adds to the island nation’s existing combination of shore sensors and ships at sea. Furthermore, the MARSEC USVs free up larger vessels to perform more complex and longer-range missions.
MINDEF also indicated, “The RSN will continue progressive experimentation to enhance the MARSEC USVs for a wider range of maritime security operations in Singapore’s congested waters.” One future role is likely to be mine countermeasures, as the vessels can carry a 20ft container or other mission module on their stern deck.
The MARSEC was developed jointly by the Defence Science & Technology Agency, DSO National Laboratories and ST Electronics. The hulls were reportedly manufactured by Lung Teh in Taiwan, before ST Electronics integrated systems.
Twin diesel engines coupled to waterjets power the Singaporean USV to speeds exceeding 25 knots, and they have at least 36 hours of endurance. Equipment includes a strobe light and siren, searchlight, Rafael Toplite electro-optical sensor, Genasys long-range acoustic device, Hitrole 12.7mm remote weapon station paired with a laser dazzler, and navigation radar.
Three MARSEC vessels have been delivered to the RSN so far, with a fourth example due this year. All are based at Changi Naval Base.
Singapore is investing heavily in uncrewed systems. For example, six Multirole Combat Vessels (MRCV), the first of which is due to enter service in 2028, will act as motherships for aerial, surface and underwater unmanned systems.
