After swimming the heat of the 4 × 200 m freestyle relay at the 2001 World Aquatics Championships in Fukuoka, Japan, Hass was a spectator for the final, when the Australians set a world record of 7:04.66 mins. He went on to swim in the semifinal of the 200 m backstroke finishing 9th. At the 2002 FINA Short Course World Championships, Hass won a gold medal for Australia as part of the 4 × 200 m freestyle relay, swimming alongside compatriots Leon Dunne, Todd Pearson and Grant Hackett.