Born: June 4, 1925; Died: April 15, 2012.

Donald Macdonald, who has died aged 86, was an expatriate island Gael with the spirit of the sea in his blood. It took him from his birthplace on Benbecula across the world with the Royal Navy and later to Canada and exploration of the notorious Northwest Passage.

As a naval physician he saw active service in the Far East and witnessed the effects of the nuclear devastation in Nagasaki. On dry land his early career featured tabletop appendectomies and babies delivered in blizzards, coming to a close with a post as a Canadian Government director of environmental and occupational health.

And wherever he went the Scottish diaspora ensured an encounter with a distant relative or friend, be it bar owner, policeman, churchman or sea captain.

Though his roots were in the Outer Hebrides, where he was the only child of the Rev Donald and Rachel Macdonald, he grew up with his mother and her family on the Inner Hebridean island of Islay after his father died from tuberculosis when he was four.

It was on Islay that he learned to love and respect the sea, spending his free time fishing and sailing. Mr Macdonald, whose first language was Gaelic, also spent some time in Bearsden, East Dunbartonshire, but was educated at Marr College, Troon, leaving school in 1942 and going on to study medicine at Glasgow University.

He graduated in 1948 and took up a post at Glasgow Royal Infirmary. Two years later he accepted a position as surgeon lieutenant in the Royal Navy, serving on HMS Jamaica.When the ship was attacked by North Korean gunboats he played his part in the rescue of the dead and wounded and care of the casualties.

A spell at HMS Tamar, the naval shore base in Hong Kong, followed until September 1952. There, as well as serving as base medical officer he also helped out locally. And during his time in the Far East he visited Nagasaki, where he saw for himself the population's ongoing medical problems follow the dropping of the nuclear bomb several years earlier. Emotionally affected by the experience, he would often say later: "I looked down and saw a green blade of grass growing. I knew there was hope."

While in Hong Kong he met his future wife, Dorothea, the full-time head of the Army Children's School Overseas, at a cocktail party. Their marriage in December 1951, reportedly the first wedding hosted by the officers' mess after the war, was a lavish affair.

His last two years in the Royal Navy were spent at HMS Raleigh's shore base in the UK. He then worked briefly at Falkirk Royal Infirmary before moving, in 1955, to Yorkshire, where he was involved in family medicine for more than a decade. During that period he spent a considerable amount of time studying pneumoconiosis, or black lung disease, and treating patients suffering the coal workers' affliction, which probably marked the start of his interest in occupational medicine.

But he was always a man with a sense of adventure and when the opportunity of working in Canada arose he was delighted. He moved to Winnipeg in 1966 where he worked in a family practice with two colleagues. However, finding himself in the middle of North America, he missed the sea, and did not think twice when the chance came, in 1970, to serve as medical officer on board the survey ship Baffin. It was the flagship of the Canadian Hydrographic Service and was involved in the exploration of the Arctic waters of the Northwest Passage, carrying out key underwater survey work in the hazardous, ice-bound region.

He joined the ship in Halifax, Nova Scotia, and loved the Arctic, its people, its wildlife, the beauty and sense of mystery. He would later recall the eerie, sometimes deafening, sound of the ship groaning and creaking as it broke through the ice sheets, and laughed at the memory of becoming lodged in the ice: "We could just lower the ladder and get off to explore."

Shortly after the trip he decided to move to Halifax where he had forged many friendships among his shipmates. He opened a family practice in Prospect Bay and became a consultant for the Workers' Compensation Board of Nova Scotia, later accepting a position with the federal government, as director of environmental and occupational health for the Atlantic Region, from which he retired in 1990.

Fiercely proud of his Scottish roots, during the 1970s he and his wife became regular fixtures in the audience of the hugely-successful Canadian Broadcasting Corporation's series Ceilidh, which was broadcast from Halifax.

They also became firm friends with the programme's host, Gaelic singer Alasdair Gillies, and visited his home in Scotland.

"Donald had such a fantastically warm personality and he never lost his gentle Highland ways," said Mr Gillies. "He was really a very special person."

He is survived by his wife Dorothea, daughters Anne and Rona and four grandsons.