An unmanned ship could be much simpler in design than a traditional one. Photo taken from BBC
Unmanned cargo ships could become a reality on our oceans within the decade, according to manufacturer Rolls-Royce.
The firm has been showing off the designs for its concept crewless ships.
The EU is funding a 3.5m euro (£2.8m) project dubbed Maritime Unmanned Navigation through Intelligence (Munin) which aims to develop its own autonomous ship.
Experts remain divided over whether such vessels will become a reality.
Writing about the future of shipping Oskar Levander, Rolls-Royce's vice president of innovation, engineering and technology said: "Now it is time to consider a road map to unmanned vessels of various types. Sometimes what was unthinkable yesterday is tomorrow's reality.
"Given that the technology is in place, is now the time to move some operations ashore? Is it better to have a crew of 20 sailing in a gale in the North Sea, or say five in a control room on shore?" he asked.
A remote-controlled ship would look quite different to a traditional one, he added, largely because there would be no need for the facilities and systems currently needed for a crew.
"Eliminate or reduce the need for people and vessels could be radically simplified," he said.
According to Moore Stephens LLP, an industry consultant, crew costs account for 44 percent of total operating costs for a large container ship.
Maritime transport has seen significant spikes in volumes in recent years and shipping is now worth $375bn (£224bn) annually.
There are approximately 100,000 merchant ships in operation around the world with certain areas of water - such as the English Channel - clogged with vessels.
Unmanned ships are currently illegal under international law, according to Simon Bennett, a spokesman for the International Chamber of Shipping, an industry representing more than 80 percent of the global fleet.
"It would require a complete overhaul of the regulatory regime. Apart from the safety considerations, there would also be a lot of questions from bodies such as trade unions," he told the BBC.
"While I wouldn't dismiss it completely, realistically it is hard to see remote-controlled ships without any crew for two to three decades," he added.
But there is, he said, intense debate in the shipping industry at the moment about the use of e-navigation - using computerised systems to navigate ships from dry land.
The ships would still have crews but some of the operational control would be moved to a system known as vessel traffic services, he explained.
For now Rolls-Royce's plans for robot ships remain at the concept stage but it is busy showing off its paper designs in the hope of persuading the industry that such change is inevitable.
And it has precedents from other transport industries.
Car manufacturers, from Tesla to Nissan and Daimler have promised self-drive cars will be on the roads by 2020 or sooner.