Great Barrier Reef placement

[jstanlis]

I am trying to create a custom map, and for the life of me I can't seem to place the Great Barrier Reef anywhere.
I've tried the "plot" and the "place" options, and with "place" the entire map is red. Not one single green place to position this wonder.

I have ample coast tiles.

Anyone have any ideas? Does it need to be adjacent to something else?