Are you leaving from Bundaberg, or the river mouth? 3 days 2 nights might be a bit optimistic if just travelling during the day. But if you got lucky, Burnett River mouth - Hervey Bay - Pelican Bay (Inskip Point) - Mooloolaba.
September is still probably a bit early to be able to catch a northerly, so you will most likely be motoring into a Sou Easter for most of the trip. I'd allow 5 days, if you do it inside that, then that's great.
Many factors to consider:
Winds, Tides, your vessels draft and so on.
The main issues around the Great Sandy Straits are riding the incoming tide down to the halfway point at Ungowan, then ride the outgoing tide to Pelican Bay. This should ensure you have enough depth. I've done it a few times with a draft of 2.1m, no problems.
Then of course, Wide Bay Bar will be fun for you the first time.
Don't be too scared, whilst we need to be cautious, don't let anxiety take over - Enjoy the adventure!
If you pay for my airfares from WA, I'll give you a hand!
