For her duties as a supply ship, St. Roch was built with a strong wooden hull, shaped to survive in thick ice. This hull made her well-suited to a role in Arctic exploration and discovery, although at 104 feet in length, she was small and cramped for this duty. St. Roch was rigged as an auxiliary schooner, using sails to supplement her engine when the wind was right. Like the more famous US cutter Bear, St. Roch served as an all-purpose roving outpost in the Artic - supply ship, post office, hospital, police station, court, and more.

After 12 years of routine service in the Arctic, St. Roch began her first and most important exploit - a west-to-east voyage through the Northwest Passage. This voyage was announced as a demonstration of Canada's sovereignty along that route - but the real motivation for the voyage was a deep secret, only revealed in recent years. The decision to send St. Roch through the Northwest Passage can be traced to the events of World War II in Europe, and the urgent need to protect war industries from enemy action. A critical (but virtually unknown) industrial resource was located in the Danish colony of Greenland - a cryolite mine. Cryolite (chemically, sodium aluminum flouride) is a key ingredient in the production of aluminum, and the Greenland mine was the sole source available to the Allies. With the fall of Denmark to Germany, the Greenland colony and mine were left essentially unprotected, and there was great fear that Germany might capture or destroy the vital mine. Such an act would have completely crippled the Allied war industry, and could have altered the course of the war.

To guard against German attacks on the cryolite mine, Canada and Britain began making plans to defend the mines, and even to occupy Greenland. St. Roch was quickly recognized as being vital to such plans, thanks to her ability to operate in heavy ice - she was the only vessel of her type owned by the Canadian government. It was soon decided that St. Roch should be sent through the Northwest Passage so she could assist in any occupation or other action in Greenland.

Even before St. Roch sailed from Vancouver, the United States had objected to any Canadian or British intervention in Greenland. This objection was partially based on longstanding foreign policy, but there seems to be an element of commercialism as well. The US aluminum companies were in competion with the Canadian companies for cryolite, and there was a fear the Canadians would monopolize the supply. US objections lead to a decision in May of 1940 to cancel all active Canadian efforts to install forces in Greenland. This decision was made before St. Roch got underway for the Northwest Passage - yet her voyage was not cancelled. Apparently, it was felt that she should still be moved to the east coast, for use in the event an occupation of Greenland became necessary at a later date.

Thus was born now-famous voyage of St. Roch - but the true reasons were kept as a closely-held secret. Not only was it essential to keep the secret from the Germans, but from the United States as well, to prevent a diplomatic incident. Of those aboard St. Roch, apparently only her captain, Sgt. Henry Larsen, knew the true purpose of the voyage. He carried this knowledge to his grave, and the facts of the situation have only recently become known, thanks to the release of long-classified documents.

Although many ships had attempted the Northwest Passage over the centuries, only one ship had completed such a voyage previously. St. Roch got underway from Vancouver on June 23, 1940, and headed north. As winter approached, she was frozen in the ice in September, and didn't move again until July of 1941. She struggled on through the ice, finally reaching Halifax on October 11, 1942 - over two years after sailing from Vancouver. St. Roch became the second ship to traverse the Northwest Passage, and the first to make the trip from west to east.

By the time she arrived at Halifax, the secret purpose behind her voyage had been overtaken by the events of war. With the US entry into the war, there was no longer any dispute over the protection of Greenland. US forces could fully and openly assume responsibility for the protection of Greenland, ensuring the safety of the cryolite mines. The Canadian plans faded into history.

St. Roch's next adventure came in 1944 - a return trip through the Northwest Passage. This time she followed a more northerly route, and completed the 7,295 mile voyage in a remarkable 86 days. Arriving at Vancouver on October 16, 1944, she became the first and only ship to traverse the Northwest Passage in both directions. It is believed that this record still stands.

In 1950 St. Roch sailed to Halifax, Nova Scotia via the Panama Canal. This voyage brought her back to the start of her 1944 Northwest Passage trip, making her the first ship to circumnavigate North America. In 1954 St. Roch reversed the journey, returning to Vancouver and completing a second circumnavigation, in the opposite direction. St. Roch was the first ship to circumnavigate the continent in both directions.

On her final return to Vancouver St. Roch was acquired by the City of Vancouver as a museum ship. She was brought ashore for preservation in 1958, and restored to her 1928 appearance. In 1966 Parks Canada constructed a permanent indoor home for St. Roch, and in 1971 completed a restoration to her 1944 appearance. Today St. Roch is the centerpiece of the Vancouver Maritime Museum. The Museum is operated the Vancouver Maritime Museum Society, and receives about half its funding from government grants, and the remainder from a variety of private sources, including admissions, fees, and donations.

Despite her illustrious history, St. Roch faces an uncertain future. The ship, and the exhibit hall where she is displayed, both suffer from dry rot, and extensive restoration is neccessary. The Vancouver Maritime Museum has sponsored the Voyage of Rediscovery to raise awareness about St. Roch, and has started a fundraising campaign to pay for the restoration.