He coxed the Scotch first VIII to victories in 2010 and 2011 APS Schools Head of the River (Victoria), as had his father Michael Sim in 1978 and his grandfather Bob in 1941.
From 2013 to 2017 Sim attended the University of Washington where he coxed the men's senior eight at various varsity regattas, including a IRA championship win in 2015.
In Australia, Sim's representative debut for his state of Victoria came in 2021 when he was selected in the Victorian men's senior eight which contested and won the Kings Cup.
[4] Sim was first selected to represent Australia in a coxed four at the 2011 World Rowing Junior Championships at Eton Dorney.
[5] At the World Rowing U23 Championships in Linz in 2013 Sim steered an Australian coxed four to an overall fourth place.