Charles, the second son of Frederick Cavill, was "Australia's pioneer in the endurance swimming field," stated the Daily Mirror, and the first man to swim the Golden Gate in San Francisco, Califomia, in September 1896."Swimmer C. Cavill seems to have struck a happy hunting-ground in American waters," wrote The Bulletin. "His 'Frisco trip did not eventuate in anything noteworthy; he had only one quarter-mile race, and a showman swim across the Golden Gate. Cavill returns to America in April to prosecute a considerable programme. He is a good long distance swimmer, and whether he is the best long-distance swimmer in Australia is a question which this country would rather concede than put to the test. This country can't stand long-distance swimming, or 25-mile bicycle races, or a week's club-swimming, or a long sermon, or any other thing which from its nature is liable to merge itself into eternity.
"Cavill was a magnificently proportioned young fellow, and an accomplished long-distance and trick swimmer As a teacher of swimming, too, his equal was difficult to be found," declared the SMH. In 1897 he won the championship of America, over a quarter of a mile in six minutes 13 seconds. The Daily Telegraph reported, "He undertook another very risky swim - around the 'Seal Rocks', just inside 'Frisco Harbor. Cavill's performance was witnessed by a very large assemblage of people, variously estimated at from 30,000to 40,000." Charles twice swam around the Seal Rocks. "Prior to Cavill's success many others had failed, and some lost their lives the paper added.
The report of his death created a sensation in Sydney swimming circles. He was apparently having a 28 mile swim along the beach at Stockton, near San Francisco when he drowned. "Frisco waters are bleak swinning almost any month of the year," annonced the Bulletin. "Champions in every field are continually pushed forward by the necessity of beating their own records, and by-and-by they touch climax and another human fly is flicked off the wall of the impossible."