Exmouth WA is another spot worth looking into. Generally looked at as one of the starting areas for WA pilots - I’ve just finished 2 seasons up there.
Usually the best time is around Nov/Dec when they start looking for pilots for the next season but still well worth a shot. Norwest (Shark Bay) Aviation, Ningaloo Aviation, Coral Bay (not sure exactly who runs it down there) and Ningaloo Whaleshark Swim are all options worth a look.