McGrath took up paracanoe in December 2013. He originally competed in V1 (Va'a Outrigger Canoe) in the TA (Trunk and arms category). In 2014, he won the Australian and Oceania Championships in V1 200 m, 500 m and 1000 m events. He is now classified as a KL2 paracanoeist. Almost two years after losing his legs in Afghanistan, he won the gold medal in the V1 200 TA event in world record time at the 2014 ICF Canoe Sprint World Championships in Moscow, Russia. After winning the gold medal McGrath commented: "Even when I was on the stretcher getting carried to the medevac chopper I said I was going to be in the Paralympics, and this is the first step". His aim is to compete at the 2016 Summer Paralympics, where paracanoeing makes it debut. In September 2014, he captained the Australian Team at inaugural Invictus Games in London, and won a bronze medal in swimming and made the archery final.