Sydney Cavill (1881–1945) was the son of the Swimming professor Frederick Cavill and 220 yards amateur champion of Australia at the age of 16. He is credited as the originator of the butterfly stroke. He followed his famous brothers to America and coached notable swimmers at San Francisco's Olympic Club.
The Cavill Family from Australia collectively inducted as Honour Swimmers in 1967 in the International Marathon Swimming Hall of Fame and in the International Swimming Hall of Fame. The Cavill Family consists of two generations of six colorful champion swimmers (1897 – 1938) who promoted swimming and set national and regional records including father Frederick Cavill, and sons Ernest Cavill, Charles Cavill, Percy Cavill, Arthur Cavill, Sydney Cavill and Dick Cavill.
Children of Frederick Cavill
- The eldest son Ernest Cavill (1868-1935) was the 1000 yards champion of New South Wales at 15 and was placed in championship races in London.
- Charles Cavill (1870-1897) was the first man to swim the Golden Gate in San Francisco in 1896, but was drowned next year at Stockton Baths, California.
- Percy Cavill (1875-1940) was the first Australian to win a race abroad when in 1897 he won both the 440 yards and the long distance (5 miles) events in the English Amateur Swimming Association Championships. He also won four State and four Australian championships in 1895-98, but left for the United States in 1900 and coached swimmers for fifteen years, before disappearing, and living as a beachcomber in the Bahamas.
- Arthur Cavill (1877-1914), known as 'Tums', won the New South Wales 500 and 1000 yards amateur championships. At 21 he was 220 yards professional champion of Australia; W. F. Corbett credited him with originating the crawl stroke. In 1901 he went to the United States: he successfully swam the Golden Gate but was frozen to death in 1914 trying to swim Seattle Harbour.
- Sydney Cavill (1881-1945) was 220 yards amateur champion of Australia at 16 and was the originator of the butterfly stroke. He followed his brothers to America where he coached notable swimmers, mainly at San Francisco's Olympic Club.
- Cavill's three daughters were also outstanding swimmers including Madeline Cavill, Alice Cavill, and Fredda Cavill.
- The youngest son Richmond Theophilus (1884-1938) was born on 16 January 1884 in Sydney. He was the first to use the crawl stroke in a competition when in 1899 he won the 100 yards State championship. In 1900-04 he won 18 Australian and 22 New South Wales championships. In England in 1902 he was the first officially to swim 100 yards in under a minute, clocking 58.6 seconds. After living in New Zealand and the United States, Dick returned to Australia in 1913 and for a time played 'Father Neptune' in Wirth's circus. He died of a heart attack at the pool he leased at Balmoral, Sydney, on 2 May 1938.
- International Marathon Swimming Hall Of Fame Origins
- World Professional Marathon Swimming Federation History
- International Marathon Swimming Hall of Fame
- Open Water Swimming
- World Open Water Swimming Association
- WPMSF Led To IMSHOF
- World Professional Marathon Swimming Federation
- Marathon Swimming
- Daily News of Open Water Swimming
- International Swimming Hall of Fame website
- Nicknames In The Open Water Swimming World
- Do You Know Nicknames Of Open Water Swimmers
- The First Dál Riata Channel Attempt In 1878
- The Legacy Of Frederick Cavill
- Olympic Club Swimmers, A Look Back