He competed in the 1990 Commonwealth Games, 1991 World Champs and the 1992 Summer Olympics.
[1] Percy represented New Zealand at the 1990 Commonwealth Games held in Auckland where he finished 5th in the 100 metre backstroke in a time of 57.89 behind compatriot Paul Kingsman who finished 3rd, and winner Mark Tawksbury from Canada.
[2] Following the Commonwealth Games, Percy swum for Arizona State University under Ron Johnson during which time he earned All-American status in 1993 and 1994 in the 200 metre backstroke and 200 metre individual medley[3] graduating in 1994 with a Bachelor of Science.
[4] In 1991, Percy raced at the World Championships in Perth with a 4th place finish in the consolation final in the 100 metre backstroke in a time of 57.52, and a 17th place finish in the heats of the 200 metre backstroke in a time of 2:05.04.
[10] After retiring from swimming, Percy returned to ASU as an assistant coach.