The fella who owned my boat previously came unstuck in a rather painful way going through that river mouth. I'd be talking to the locals and doing some web research.

 from what i have heard you wont want a boat that is under powered. follow another small boat out there and come back in on the same lines you went out on but you need to gunn it or the swell could push you onto the reef. this is all going on what a friend has told  me when we were thinking of going there.dont follow the big cray boats out as they tend to take shortcuts

I wouldnt be taking a bout out under 17 feet. Used to live there, seen many people come unstuck. Many have died. As Faulkners have said. Follow another small bout out and come back in with another. The mouth looks totally different going out to what it does coming back in.