I see QPS have located the main wreckage more or less where they expected, NNE of the island. No bodies there though.
Michael's wx scenario makes the most sense so far, although if I read the time correctly, the radar didn't look bad. On an unrelated note, I see that another Cessna, a 206 went for a swim in Qld waters today. This time off Fraser, 2 POB, both fine if a little damp.