When you reach the airport exit turn right and continue on till you reach the third roundabout.
The ferry arrives early in the morning and most people choose not to have breakfast on board as that's even earlier. Take a thermos if you really need an early morning cuppa. After the quarantine inspection as you leave the arrival area you will receive a plastic bag containing tourist information, including a map inside the back cover of Treasure Island.
When you leave the airport, turn left and continue until you reach the outskirts of Evandale.