Waterhouse became a barrister in 1948 but took leave of absence in 1954 after the sudden death of his brother and partner, Charles, and never returned, making bookmaking his full-time career.
[2][self-published source] He engaged in betting duels with giant punters such as Frank Duval (Hong Kong Tiger), Filipe Ismael (The Filipino Fireball) and Ray Hopkins.
[3][self-published source] A man of large stature, he was dubbed 'Big Bill' and 'king of the bookies', remaining at the top for over 20 years.
Media coverage of him included articles in The Bulletin, the former National Times, The Sydney Morning Herald Good Weekend and in TV specials such as A Big Country and an interview by David Frost.
[2][self-published source] In 1968, the Victoria Racing Club changed its rules to disallow bookmakers operating in other states fielding on-course bets in Victoria, initiated in part as a result of allegations against Waterhouse that he was taking illegal off-course bets, subsequently dismissed by a Magistrate.
[4] Waterhouse was cleared of rumours surrounding the doping of Melbourne Cup co-favourite, Big Philou in 1969, when it was shown by Australian Jockey Club (AJC) officials he was not working on the race, by then being a Sydney bookmaker and did not stand to lose on Big Philou in the doubles business run by his staff.