Hi Mick,
Well a 4.55 isn't exactly huge so you'll have to plan carefully what you're taking along. Start with the critical stuff first - water, food, communication (radio, epirb, mobile) and then move on to secondary stuff like swags, shade, cooking utensils etc. I always imagine myself sitting in front of the camp looking around at everything. As I "see" things I write it down. Sounds silly but works!
Just keep an eye on the total weight because overloading the boat is pretty dangerous and the handling will go to shit. I'd suggest maybe going for 1 night only the first time.
As for anchoring the boat there are a few options.
1. Plan your trip to coincide with tides and let the boat bottom out overnight and get it early morning on the rising tide.
2. Employ a endless loop system (see http://www.ausfish.com.au/vforum/sho...d.php?t=146805) Unfortunately this takes some time to set up and might not work if the boat is very far out.
3. Take along a small kayak. We did this and it worked brilliantly, and is also fun to just potter around the shallows.
Whatever you do, do not try to swim any great distance to retrieve the boat! Apart from the crocs it's very easy to underestimate the distance (and overestimate your ability) and get into trouble. This means the missus will go into a flat panic and try to help, getting her into trouble as well.
Remember the bug spray!