China appears to be testing a stealthy new trimaran at sea, according to a photograph circulating on social media, in what could be a further effort to develop unconventional naval platforms.

The image first emerged on Weibo on Sunday and appears to show a vessel featuring an inverted wave-piercing bow, three-hull design and angular superstructure surfaces that could be intended to reduce its radar signature.

The vessel, which is fitted with a prominent antenna mast and multiple dome-shaped structures that resemble radars, is pictured at sea with a distinct wake, suggesting it is moving at speed.

However, the time and location of the picture have not been independently verified and details about the boat’s specifications, intended role and operational status remain unclear. China has been developing a range of trimaran vessels with various designs and capabilities, including many that are uncrewed.

At the Zhuhai air show in 2024, it unveiled the JARI-USV-A, also known as the Orca, or Killer Whale, a 58-metre (190-foot) long, 500-tonne stealthy trimaran uncrewed combat vessel, which is designed with a maximum speed of more than 40 knots (74km/h) with a range of more than 4,000 nautical miles (7,400km).

The Orca can reportedly carry a range of weapons – including rockets, anti-ship missiles and ship-to-air missiles – and is equipped with a helicopter landing pad at the rear. Although it can carry crew, it is designed to operate independently and could undertake patrols, anti-submarine operations and air-defence work as well as rescue operations. Following its public debut, it has been spotted conducting several sea trials since last year.

Earlier, in June 2022, another domestically developed trimaran uncrewed surface vessel completed its maiden autonomous sea trial off Zhoushan. It had a displacement of about 200 tonnes and was designed to test autonomous navigation and other intelligent technologies.

Satellite imagery revealed a further unusual, dark-coloured trimaran vessel under construction at the Huangpu shipyard in Guangzhou in October last year. Measuring about 65 metres long and largely concealed beneath tarpaulins, the vessel reportedly featured an unusually slender hull and had two outrigger hulls positioned near the very back.

The Naval News website reported that the vessel was likely to be uncrewed or minimally crewed and potentially designed for high-speed operations.

Possible roles include serving as a semi-submersible arsenal ship capable of carrying a vertical launch system for missiles, or as a platform for deploying drones or other uncrewed systems.

The latest sighting, if confirmed, would add to a growing list of these experimental uncrewed or optionally crewed vessels developed by China in recent years.