Cahills Crossing Arnhem Land

He is referring to the Tidal predication table high and low. The problem is how does this relate to the crossing, the crossing level will be dependent on the tide level and the amount of water flowing down the river.

.
Ah yes, thanks Leigh. Somehow I imagined that Ken was referring to a sign at the crossing.
Yes, of course the the charts would be referencing a nominated location on the East Alligator River but that would only help ascertaining when the level at the crossing would be at its lowest, not the actual level. The tide information may assist a person to plan a crossing time then observe the depth indicator boards when they arrive.
The other often employed method is to just rack-up anytime and take a break while watching others cross before taking the plunge, errr, so to speak.

Hi Allan
That is an interesting point. Tide times and heights taken somewhere else still need local knowledge to interpret, as you suggest it "may assist a person to plan ..."
Many years ago we spent a couple years living on our yacht at Maryborough Qld. Tide information was quoted at River Heads somewhere I think (doesn't really matter). The thing is, we knew how many hours difference there was between what was quoted and what happened in reality at both high and low tides at Maryborough so far up stream. An interesting quirk was that high and low water did not coincide with the change in current.
This was problematic for several yachties like us with deep draft vessels who wanted to use a local slipway. We needed the highest point on the tide (and a king tide at that) but by then the current was already running out quite strongly. Quite a trick holding a large yacht at right angles to the current and lining up with the slip. Probably easy for a twin screw motorboat with a bow thruster.
Just saying that tidal rivers need local information to know what to expect at any given point.
I think your last point is safest, 'observe and wait'.
Cheers
Roy G
Toowoomba (now on the road full time)