A robot boat with no crew has given a glimpse of the future after completed a three-week mission mapping the Atlantic seabed.
Maxlimer - which was skippered remotely from the UK - journeyed out into the ocean to chart an area of seabed 3,280ft (one kilometre) below the surface.
The Uncrewed Surface Vessel (USV) was originally developed for a competition, but is now showcasing future ways of working at sea in a mission part-funded by the European Space Agency.
After setting off from its base in Plymouth in late July, the 12-metre long Maxlimer travelled 280 miles (460km) to the south-west, skippered via satellite from its base in Tollesbury in eastern England.
The boat is equipped with a multi-beam echo-sounder attached to its hull, which was used to map a segment of seafloor that had essentially no modern data registered with the UK Hydrographic Office.
SEA-KIT International developed the craft, which won the Shell Ocean Discovery prize in a competition to find next-generation technologies that could be used to map the global ocean floor.
Only one fifth of the Earth's sea bottom is currently surveyed to an acceptable resolution.
Many big survey companies that run traditional crewed vessels have started to invest heavily in these kinds of futuristic, remotely operated technologies.
There are also expected to be advantages for freight companies from running robot ships.
The Maxlimer mission was being used as a test to show that 'over-the-horizon' control technology is practical and safe.
And SEA-KIT's director of technology Peter Walker said the mission had proved a success.
"The project's overall aim was to demonstrate the capabilities of current technologies to survey unexplored or inadequately surveyed ocean frontiers and despite the planning challenges we faced due to Covid-19, I feel that we have done that," he said in quotes reported by the the BBC.
"We have proven the true over-the-horizon capability of our USV design and the team are exhausted but elated."
Maxlimer moves slowly, at up to 4 knots (7km/h; 5mph), but its hybrid diesel-electric propulsion system is highly efficient. The vessel returned to its base with the fuel tank still a third full.
SEA-KIT CEO and designer, Ben Simpson, told BBC News: "We had a sweepstake on how much fuel would be left in the tank. We thought there was going to be 300-400 litres. It turned out there was 1,300 litres."
As well as the European Space Agency, partners on the project included Fugro, Global Marine Group, Map the Gaps, Teledyne CARIS, Woods Hole Group and the Nippon Foundation-GEBCO Seabed 2030 initiative.
