Background
He was born in Victoria, British Columbia in 1901 and attended the Royal Naval College of Canada in 1915 during the First World War.
He was born in Victoria, British Columbia in 1901 and attended the Royal Naval College of Canada in 1915 during the First World War.
With the start of the Second World War he took command of HMCS Assiniboine and then HMCS Ottawa before being promoted to Captain and taking overall command of Royal Canadian Navy (RCN) destroyers in Halifax in 1941. In 1942 he was appointed acting Commodore and took command of RCN destroyers in Newfoundland, quickly followed by an appointment to Ottawa as Chief of Naval Personnel. He returned to active duty as the commanding officer of HMCS Uganda in 1944.
As a part of British Pacific Fleet Uganda took part in the Okinawa campaign.
In the post-war years Mainguy was appointed Flag Officer Pacific Coast in 1946, Flag Officer Atlantic Coast in 1948, and was the head of the commission that investigated the RCN insubordination incidents of 1949 before becoming Chief of the Naval Staff in 1951. He retired from the RCN in 1956 as a Vice-Admiral.
He died in 1979.
