A British Sea King helicopter, like this one, had to be specially adjusted to make the long-distance flight to pick up an injured Canadian seaman in the North Atlantic. (Ministry of Defence)

A British military search and rescue helicopter made a dangerous long-distance flight over the North Atlantic on Wednesday to provide urgent medical transport to a Canadian navy sailor injured at sea.

A British Sea King flew about 300 kilometres off the western coast of Ireland to meet a Canadian naval vessel carrying the injured sailor.

The 50-year-old sailor had crushed his hand in one of the ship's steel doors and was in urgent need of medical attention, according to Canadian navy officials.

The sailor was a crewman aboard HMCS Montreal, which was part of a four-ship Canadian naval task group on its way to Glasgow, Scotland, to participate in international naval exercises.

Maj. Paul Doucette, spokesman for Maritime Forces Atlantic, said the Montreal did not have a Sea King helicopter aboard.

Instead, Doucette said the Montreal broke away from the task group and raced east toward Ireland. In the meantime, British authorities had been contacted and had been asked for assistance.

The British Royal Air Force responded. It stripped excess gear off one of its 1977-era Sea Kings in order to increase its range, and dispatched it over the North Atlantic to meet the Montreal.

At the time, the weather at sea had deteriorated to such a degree that the Sea King crew had difficulty locating the Montreal, the British Defence Ministry said.

But using its radar, the British crew was eventually able to find the Montreal and land on its deck to pick up the injured Canadian sailor.

The helicopter then flew to Ireland, where the Canadian sailor was sent to hospital for surgery to save his hand.

"He's OK," Doucette said.

Britain's Defence Ministry described the incident somewhat differently. A news release distributed by the department said the mission was a "dramatic search and rescue mission that saw a Canadian seaman saved by a Royal Air Force crew."

It said said the Montreal had sent out a "distress signal" after it encountered difficulties off the coast of Ireland.

Doucette said the British news release was overstating the case. He said no distress signal was sent. Rather, the Canadian ship had sent a request for medical assistance.

Doucette said that at no time was the Montreal in any difficulty.

Doucette added that the Montreal recently had its hangar, flight deck and flight systems updated in anticipation of the arrival of new maritime helicopters, called Cyclones.

The first Cyclone is expected to be delivered to the Canadian Forces in November.

But as a result of the upgrades, Doucette said, the vessel was unable to carry its own Sea King. In fact, only one of the three other Canadian ships in the task group is equipped with a helicopter.

Doucette said that didn't make a difference in this case as the task group was too far out in the Atlantic for a Canadian helicopter to reach shore.

The Canadian task group is expected to return to its home port in Halifax by the end of the month.