We did it this past July/August. Didn't see more than 2 crocs: they are said to be relatively quiet before September. We have a rubber
dinghy, so we lifted it up every evening: no problem.
Best river to go up is King George: relatively easy to enter and navigate, wonderful scenery and short enough so you don't waste too much
fuel. You can easily go all the way up to the falls at the end.
We met few other boats, and all were very nice. Rarely went more than a week without seing somebody :-)
Excellent stop at Silver Gull Creek: very easy to fill-up with excellent
water. Next door, Dog Leg Creek is convenient to fill-up with
diesel (AUD2.5/l), as there is no easy way to get
fuel in Broome.
Recommended stops: King george, Freshwater bay for a swim, Bigge island for the rock art, Shelter bay (Prudhoe island) for scenery, protection and
fishing, Sampson inlet, Beagle bay and many others in-between.
Don't count on catching much
fish while trolling under way. Works better from the
dinghy.
No local population to speak of, but bush fires were a problem in some areas: smoke and ashes.