China is developing unmanned marine equivalents of drones to strengthen its power at sea.
Government funding of robotic vessel research has increased dramatically, mainly from the military, according to scientists involved in the work. At least 15 research teams have been set up at top universities and research institutes to produce the high-speed unmanned vessels over the past couple of years, scientists said.
Professor Ma Zhongli, robotic vessel expert at Harbin Engineering University, said the government had invested intensively in UAVs, or unmanned aerial vehicles or drones, over the past few decades. Only recently did the authorities realise the practical value and strategic importance of unmanned marine vessels.
Ma said the military was particularly interested in using the vessels for intelligence gathering and drawing enemies’ fire in sea battles. They will be able to carry various payloads from infrared cameras to missile launchers. 
“The government’s biggest interest is in the application’s use in the military,’’ she said.
“They can patrol on water tirelessly 24 hours a day, seven days a week. They can see things in the distance that it’s impossible to see with human eyes.
They can be deployed immediately in enormous numbers to overwhelm the enemy. Most importantly, they can reduce casualties. The situation in some waters can become too sensitive or too dangerous to send men in. That’s when they need our boats the most.’’
Ma said the vessels also had a wide range of uses in the civilian sector such as environmental protection and fishery management.
One of the most important challenges facing Ma’s team is developing a camera system that can take sharp and stable images or videos, even on board a rocking boat.
A mechanical system is needed to stabilise the camera and computer software to control the lens to compensate for the boat’s motion.
The camera is needed to identify objects encountered by the unmanned vessel, including whether boats are military or civilian.
“The technology is much more difficult and sophisticated than the ones used in normal drones, which fly much more stably and predictably,’’ she said.
“Without solving these technological hurdles, robotic boats will not start mass production.’’
Research teams in other universities, such as Jiangsu University of Science and Technology, Dalian Maritime University and the Chinese Academy of Sciences, are working on other issues such as the wireless communication and coordination among large fleets of unmanned vessels.
Some researchers declined to be interviewed because of the sensitive nature of their research.
Ma said other countries such as the United States have launched similar research projects earlier than China and come up with some impressive models, but unmanned vessels might have a larger use in Chinese waters.
“China shares the sea with many countries nearby. In these troubled waters, unmanned vessels can be more effective, convenient and safe than manned ships in many situations. They will also cost less,” she said. “Their power will double if they are deployed with [aerial] drones.’’