Mocky began his career with Greymouth Marist. In 1970, Mocky joined Marist-Western Suburbs. Mocky played 11 seasons for Marist-Western Suburbs (156 tries). Mocky was a member of Marist-Western Suburbs; 970, 72-73 and 79 Grand Finals. Mocky captain-coached Marist-Western Suburbs in 1977.
Mocky played for West Coast from 1966-69. Mocky played 53 games for Canterbury from 1970-79 (46 tries). Mocky played 24 test matches for New Zealand between 1969-75 (3 tries).
Mocky served as president of Marst-Western Suburbs from 1985-91.
In 1989, Mocky was selected on the wing in the West Coast Rugby League 75th Jubilee Team. In 2013, Mocky was inducted as a New Zealand Legend of League as part of the Canterbury Rugby League centenary.