I have made a boat trip from Cairns to Fitzroy Island and back. Far away I have seen an island ( also visible from Cairns ) and a tower. I suppose, thats a lighthouse. Either I can identify the island, maybe Green Island reef, nor I can identyfy the supposed lighthouse in the internet! :(
Here is the chart of the area. This could be Green Island (there is some beacon on this island marked on the chart) or Arlington reef (but it doesn't stay on island as far as i could see). Green island is admiralty K3170.2
I think this is the mast in the middle of island on this picture https://ssl.panoramio.com/photo/83811125
:) Wonderful, I believe, you are right again. Lighthouse Directory dont list a light on Green Island. Thats the only way I search for lighthouses. Thanks, Dmitry ! Andreas