Surely the purpose of these boards is to advise the boater on state of the 'hazard' in the next section. One would not necessarily expect the two boards to give the same assessment as there are different risks in going up stream to down stream over the same stretch of water. At face value you might expect the Wychnor board to be more pessimistic as the boat is travelling upstream.. I guess it depends on how easy/difficult it is to negotiate crossing the flow above the weir. Obviously going upstream the boat is in the cross flow for longer but it is probably more difficult to steer going downstream although for a comparatively shorter time.
Richard
