in september 1883 joseph coates successfully applied for the headmastership of the soon to be established sydney boys' high school and waterhouse as head of maitland high school. sydney high opened in october 1883 and as coates could not leave newington until the end of the year, john waterhouse was appointed to open the school. his letter of appointment clearly names him "headmaster" and so he is rightly regarded as the founder of sydney high. at the beginning of 1884 he opened maitland. in 1889, he was appointed inspector of schools in the dungog region. while in dungog tragedy struck on 29 october 1894 when waterhouse's wife and daughter drowned in the wreck of ss wairarapa on great barrier island. he was left as a widower with five children under 11 years of age. (he married his sister in law in 1901.) in january 1896, waterhouse transferred to the lithgow district, but this position was to be short-lived. in july 1896, he was appointed headmaster of sydney boys' high school and became a resident of chatswood. he took on a school that had suffered as a result of the 1890s economic crisis and the degenerative illness of its first headmaster, joseph coates. over the next nineteen years, waterhouse was to lead the revitalisation of sydney high school. the enrolment increased from just over 100 in 1896 to 350 in 1906 and 422 in 1915. academic results at the public examinations during his term were outstanding and the school was admitted to the gps in 1906. waterhouse retired as headmaster of sydney high in 1915 on medical advice. his doctors had given him only two years to live. he lived to spend 25 years in retirement.