If robots had feelings, Solar Voyager would be the saddest.

The four-metre aluminum boat left Massachusetts June 1 to begin a transatlantic journey to Lisbon, Portugal. 

Solar Voyager undertook the trek alone, navigating autonomously with no crew on board.

"To anthropomorphise it, it's a very lonely journey," said Isaac Penny, one of the engineers who has spent four years building Solar Voyager.

The boat made it approximately 1,000 kilometres up the coast when it became caught in fishing equipment.

"It's basically gotten, well, we believe it's gotten tangled in a net off the coast of Nova Scotia," said Penny.

The engineering team can use a satellite signal to send Solar Voyager waypoints to head towards, but the boat chooses how to navigate. The team can't directly control the boat.

Solar Voyager automatically updates its location online via a satellite link every 15 minutes.

Penny said they designed the propellers to not snag fishing lines and to reverse direction if they do get stuck. He said the net is wrapped around one propeller and has jammed the rudder to one side.

The world's first autonomous transatlantic crossing now appears to be on hold.

"We've temporarily shut it down for 12 hours to let it drift a little bit closer to shore," Penny said.

Solar Voyager is approximate 160 kilometres from Sable Island, adrift in ocean currents.

Solar Voyager map

Solar Voyager is adrift in the ocean, after getting caught in fishing equipment approximately 160 km south of Sable Island. (Solar-Voyager.com)

Penny is currently in Singapore and unable to go rescue the boat. He said he hopes someone in the area might be able to track down and cut the robot free from the nets.

"Hopefully a fisherman can divert on the way out or on the way back," he said.

This journey would have been the first autonomous transatlantic crossing, but also the first solar-powered one, too.

"It's a very lonely journey." - Isaac Penny, Solar Voyager's co-creator

"Not only is it more environmentally friendly, it also gives you, in theory, unlimited range and unlimited endurance," Penny said.

He said autonomous solar-powered shipping could revolutionize the industry in the decades ahead. It could offer opportunities to reduce the size of crews needed to operate ships.

"It's not just an alternative form of energy," Penny said, "in this case it may be the best one."

Any benevolent boater interested in an impromptu robot rescue can contact the team at thesolarvoyager@gmail.com.