An unmanned robotic yacht launched as part of a transatlantic challenge last month has disappeared without trace after going in the wrong direction.
It was the first time scientists at Aberystwyth University had attempted the Microtransat Challenge crossing.
Pinta, their 3m long boat, set sail from Ireland and was tracked up until two weeks ago.
It travelled about 400 miles (650km), but equipment failures resulted in it sailing in the wrong direction.
Its last recorded position was around 62 miles (100km) off the west coast of Ireland.
The craft, which cost £2,500 and was built by students and academics in their spare time, was not expected to complete the crossing because of weather conditions.
But Aberystwyth University said the robot operated correctly for 49 hours during which time it sailed 54 miles (87km) and relayed its position every hour via a satellite link.
Despite Pinta's failure, the university said it believed it held the record for the longest distance and longest period of autonomous robotic sailing.
The Microtransat Challenge was conceived by academics in Aberystwyth and Toulouse, France, and Aberystwyth was the only team taking part this year.
Dr Mark Neal, one of the founders of the challenge from Aberystwyth University, said the aim was to build robots that could survive in hostile environments for long periods.
"The sailing robot Pinta has now stopped sending tracking signals after surviving for a total of 17 days during which time it travelled around 650km," he said.
"Its last recorded position was around 100km off the west coast of Ireland after a number of equipment failures resulted in it sailing in the wrong direction.
"The first equipment to fail was the satellite transmitter, which makes diagnosis of the subsequent behaviour more difficult, but the robot appears to have continued to steer itself on a constant course for a further 20 hours.
"After the 18 September the average speeds began to drop significantly implying that sail damage was beginning to have an effect."
He said Pinta would have probably capsized many times in strong winds and heavy seas, which would have been responsible for the equipment failures.
Dr Neal added: "If Pinta had travelled the same distance in the intended direction she would have reached approximately the latitude of La Rochelle (west coast of France), and would have reached much more favourable weather systems and wind directions.
"Despite her relatively rapid failure the team are pleased with her performance and will try again next year having learnt some useful lessons."
The crossing was expected to take three months.
Complete with small solar panels, the boat was programmed to sail a course but had to be propelled by just the wind.