When a young Vivian King surfaced from a learn-to-swim program at Sherbrook Pool in 1940, it marked the beginning of an illustrious competitive swimming career. King's assault on the amateur record books continued until 1951 when she shocked the Canadian aquatic community with her decision to turn professional. That same year, King married Alex Thompson and won the three mile swim at the Canadian National Exhibition in Toronto.
As an amateur, her freestyle and backstroke techniques were termed "brilliant" by coaches. Her cohorts, who trained with her at Sherbrook Pool, the Red River, or Lake Winnipeg, claimed that "she had the strength of a man in her stroke." King embarked upon an arduous training regiment with great dedication. It did not come as a surprise when King was selected to the Canadian Olympic team in 1948. At the Games in London, King finished fifth in the preliminaries of the women's 400 metre freestyle competition.
Among her many triumphs were the following: 1941 Winnipeg juvenile champion; 1944 Provincial junior 1/2 mile champion; 1945 Manitoba champion in the 50, 100, 220, and 880 yard freestyle and 50 and 100 yard backstroke; 1946 Canadian junior champion in 100 freestyle and all round Manitoba champion; 1947 won the national open 100 yard freestyle, western Canadian one mile title, and provincial crowns in three freestyle and two backstroke events; 1948 won the Canadian 400 metre freestyle title and berth on the Olympic team; 1949-51 won the Canadian one mile as well as several western Canadian, Ontario, and Manitoba one mile titles.
After turning professional, King competed in the 26 mile Atlantic City swim against men and finished fourth. Then, in 1956, as a mother of two boys, King made an eighteen mile crossing of Lake Winnipeg in a record of eight hours and forty minutes, and eclipsed the standard by more than seven hours.