Speculate as you like about what he was doing down in Australia a few days longer than Vanessa was. She came back for her lil' sister's b-day (they apparently went to Disneyland). Rumor has it Zac stuck around (maybe with his dad???) to surf. No idea where the Tizz is (or Kenny for that matter) and do not care.
Radio interview with Ash and Vanessa, but sadly no Zac. They piss Vanessa off by giving her a hard time about refusing to talk about Zac: