Members of the Royal Canadian Navy spread the ashes of two people with links to the tragedy into the icy waters of the Gulf of St. Lawrence where the civilian vessel was torpedoed by a German U-Boat in 1942.
Of the 237 people aboard the Caribou — which was sailing on its regular route from Nova Scotia to Newfoundland — 136 died in the frigid waters.
"It was warfare, and the U-boats were determined to shut down the trade between North America and Europe because they understood that (it) was going to tip the balance in who won the war," said Royal Canadian Navy Commander Larry Trim from Sydney, N.S., on Saturday.
"It was one of the most tragic events during the Second World War. It was an immense tragedy that is still felt today."
Members of the Canadian navy and Marine Atlantic officials held a ceremony during a ferry crossing from Port aux Basques, N.L., to North Sydney, N.S, Sunday afternoon to mark the sinking of seven decades ago.
Wreaths were tossed into the waters over the same spot where the Marine Atlantic vessel sank after the attack by the submarine U-69.
The ashes of Eric Andrews were spread into the waters during the ceremony. Trim said Andrews survived not only the sinking of the Caribou, but six other submarine attacks on ships during the Second World War.
"His story is amazing. He was torpedoed seven times... and the S.S. Caribou was the seventh," said Trim. "He said it was the worst experience he went through ... because there was so many men, women and children and so much confusion.
"He said the screaming of the women and children was awful."
The ashes of Robert Cutler were also spread at sea during the ceremony. Cutler's father, Howard Cutler, was the mail room clerk aboard the Caribou and was among the 31 of 46 crew members who died during the attack, he said.
Both Robert Cutler and Andrews had requested that their ashes be spread at the site.
Historical accounts say the Caribou was hit around 3:20 a.m. on Oct. 14, about 37 kilometres off the shores of Newfoundland in the Cabot Strait during its crossing from North Sydney, N.S.
Within five minutes, the ferry had sunk. Only one rescue boat carrying about 20 people made it into the water. Other survivors were left bobbing in the frigid Atlantic, clinging to debris and overturned life boats.
A warship that was escorting the ferry, HMCS Grandmere, had to hunt the U-boat before attempting to rescue survivors. The Grandmere located and attacked the sub, but it escaped.
Some historians have said the Caribou's sinking was Canada's worst naval disaster of the Second World War.
The tragic event instilled panic across Eastern Canada about whether it was safe for ships to sail in coastal waters.
Paul Griffin, president and CEO of Marine Atlantic, said it was an event that brought a war largely fought overseas to Canada's doorstep.
"This and a number of other events were close to home," said Griffin from St. John's, N.L., on Saturday. "The fact that it happened so close to our shores really impacted people at the time."
— By Aly Thomson in Halifax