An unmanned solar-powered robot boat whose propeller got snagged in fishing gear has been plucked from the Atlantic Ocean by a Canadian warship, ending its attempt to complete the first autonomous transatlantic crossing by boat.

A pair of engineers built Solar Voyager, a low-profile four-metre aluminum kayak outfitted with solar panels.

They launched it in Massachusetts at the start of June and hoped it would eventually reach Portugal.

The engineers can remotely set waypoints, which the boat then intelligently navigates toward.

Approximately 1,000 kilometres into the journey, Solar Voyager got snagged in a fishing net and spent days drifting near Sable Island.

Navy to the rescue

"We were at sea doing some exercises ... and noticed that our track was going to come very close to where we knew the Solar Voyager was located," said Commodore Craig Baines, commander of Canada's Atlantic Fleet, via satellite phone aboard HMCS St. John's.

Early Wednesday morning, the 134-metre frigate pulled alongside the Solar Voyager to investigate. After co-ordinating with the owners, the decision was made to recover the vessel.

"Based on their request and our determination that it was a potential hazard to shipping, we were able to bring it on board," Baines said.

He added that the Solar Voyager sits very low in the water and weighs 317 kilograms, making it tough to spot and possibly dangerous if a boat were to hit it.

'We're very happy'

Isaac Penny, the boat's co-creator and owner, said he's pleased with how the robot rescue went.

"We're very happy for the help that we received from the Canadian navy," Penny said.

Originally, the Solar Voyager team had sought help from any fishing boats in the vicinity.

Officials say they were able to attach hooks to the 317-kilogram boat and hoist it on board. (LS Peter W. Frew/DND)

Navy officials said they admired the ambition of the team and are glad HMCS St. John's was near enough to offer assistance.

"I think this shows our flexibility, our versatility and the importance of us being able to surveil what is in our waters," Baines said.

Same ship; many missions

This isn't the first time HMCS St. John's has intercepted an autonomous boat.

In 2011, the ship helped the U.S. Federal Bureau of Investigation and U.S. Coast Guard recover drug cargo from a "self-propelled semi-submersible."

Navy divers from HMCS St. John's work to free a humpback whale from fishing nets near the Grand Banks off Newfoundland. (Canadian Press/ DND)

During that mission, the interagency team found more than 10,000 kilograms of cocaine and 1,100 kilograms of marijuana, valued at $223 million.

In 2007, the crew of HMCS St. John's helped rescue a humpback whale that was caught in fishing gear.

Solar Voyager 2?

Engineer Isaac Penny says he still doesn't know the status of Solar Voyager.

"What is her condition? Could she continue on just with some untangling? Is there some damage? All those things, I don't know yet," he said.

Penny also didn't rule out another attempt to send an unmanned robot vessel across the Atlantic Ocean.

"I think we could do it. There's not a whole lot of reasons not to," he said.