500N:
Going back to Broome for a bit, have you actually ever seen the flying boat wrecks that are in Roebuck Bay? I went to Broome on many occasions in the 60's, several times at very low tides and, despite looking really hard, I never saw any seaplane hulks. I don't doubt they're there, just the ability to ever see them could well be an urban myth.
Mind you, there were still a lot of items of interest on the aerodrome then; bits of Hudsons and a Liberator scattered about, plus many bullet holes in Horrie Miller's hangar.