The old boy told me it first washed away, in a big way, in 74. That was when there were a sh#teload of fishing shacks up and down DI. When that cyclone in 74 rolled through and washed them away.
Teewah was subdivided and leased to those fisherman to try and keep the shacks of the beach. Joe Bielkiepeterson (sp), whilst he was in the Lands Dept. authorized the subdivision in a National Park without ministerial approval apparently in late 75 or early 76.
Back on thread, we think it closed down around 83 or 84.
You should give someone a call from the Gympie Historical Society or somewhere like that. They probably have the archives for Rainbow Beach. The southern side of DI has always been the unofficial northern end of the Sunny Coast and Rainbow was Gympie's Southern end. Off thread, my business partner told me today that his old man used to ride his pushie from Gympie to that camp at Rainbow to fish in the 60's................