I'd say where this unfortunate incident occured is Eli Creek, which can be a bit dicey as the tide comes in. Not a good time to stop for a look, as the sand just washes away from under you tyres. We've had the water way up over the bonnet of the patrol (3 inch lift) and you just have to lead foot it. He/she who hesitates is sunk. Lots of fun though.
Eli creek is the largest freshwater creek flowing down to the sea on Fraser Island. It's a great place for a swim as the currently gently pushes you down stream, and it's all sandy. Could be one in Hervey Bay, but Eli Creek is one of the famous attractions on Fraser.