Bribie sound nice, and I dont think we've been out there for a cruise, lots of nice big parks over there, depending on where you want to go.
And it is dead simple to organise a cruise:
1. State meet point and time. Meet point should be easily found by people who are not locals to it, ie Yatala BP, Morayfield BP, etc etc.
2. Figure out a route, and keep it simple.
3. Have a CB or handheld radio on the day to be able to hear what is going on behind/infront of you.
4. State length and what people will need to bring with them, ie food/chairs/warm clothes/etc.
And then turn up! easy!