The Canadian Navy has been heavy into the submarine biz for generations.
The Canucks got into subs in a weird way when in August 1914, Sir Richard McBride, KCMG, the premier of British Columbia, bought a pair of small (144-foot, 300-ton) coastal submarines from Seattle Construction and Drydock Company, an act that your local government normally doesn’t do. The boats had been ordered by Chile who later refused them as not up to snuff.
Sailing for Vancouver in the dark of night as they were technically acquired in violation of a ton of international agreements (and bought for twice the annual budget for the entire Royal Canadian Navy!) they were commissioned as HMCS CC-1 and CC-2. The Dominion Government of Canada later ratified the sale while a subsequent investigation was conducted into how they were acquired.
Nonetheless, the two tiny CC boats were the first submarines of the Maple Leaf and continued in service until after the Great War when they were laid up and replaced by a pair of American-made 435-ton H-class submarines from the Royal Navy, HMS H14 and H15, which remained in the Canadian fleet as HMCS CH-14 and CH-15 until broken up in 1927.
After this, Canada went out of the submarine business for a while until 1945. Then, Ottawa inherited two newly surplus German Type IXC/40 U-boats, sisters U-190 and U-889, both in working condition and constructed in the same builder’s yard. After transferring them on paper to the Royal Navy, they were transferred back (apparently the same day) and both became vessels of the RCN, dubbed HCMS U-190 and U-889, which they kept as working souvenirs for a couple years.

Canadian war artist Tom Wood’s watercolor depicts German sailors being transferred from U-190 on 14 May 1945. Wood, assigned to paint subjects in eastern Canada and Newfoundland, was present when Canadian ships escorted U-190 to Bay Bulls, south of St. John’s. There, Canadians removed the last of the U-Boat’s crew, who had been operating the vessel under guard. The majority of U-190’s crew had been taken onto Canadian ships at the time of the submarine’s surrender. Beaverbrook Collection of War Art. CWM 19710261-4870
Fast forward a bit and the Canadians began using two U.S. boats, —USS Burrfish (SS-312) and USS Argonaut (SS-475), as HMCS Grilse (SS 71) and Rainbow (SS 75), respectively– from 1961 to 1974.
Then they bought their first new subs since CC-1 & CC-2, a trio of British Oberon-class diesel boats– HMCS Ojibwa (S72), Onondaga (S73) and Okanagan (S74), which served from 1965 to 2000.

Three O-boats (Oberon-class) submarines of the Royal Canadian Navy in Bedford Basin, Halifax, 1995. RCNavy Image 95-0804 10 by Corp CH Roy
Since then, they have been using the quartet of second-hand RN Upholder-class subs, HMCS Victoria (SSK-876), Windsor (SSK-877), Corner Brook (SSK-878) and Chicoutimi (SSK-879) which are expected to remain in service in some form until the 2030s.
The thing is, the Canadian Navy managed exactly zero (-0-) days underway with their subs last year– but not without cause.
As reported by CBC:
“The boats were docked last year after an intense sailing schedule for two of the four submarines over 2017 and 2018. HMCS Chicoutimi spent 197 days at sea helping to monitor sanctions enforcement off North Korea and visiting Japan as part of a wider engagement in the western Pacific. HMCS Windsor spent 115 days in the water during the same time period, mostly participating in NATO operations in the Atlantic.”
It is hoped that three of the four may return to sea at some point this year.
Yikes.