Waterfall
Question: On a riverboat trip in Ghent in Belgium, I noticed that, as the bow
of our boat passed a point on the shore, the water level at the bank at that
point began to drop. We were travelling at about 5 knots. By the time the point
was amidships the level was down 10 centimetres. This was several seconds before
the bow wave reached the bank.
The effect was particularly noticeable where there were piles along the river
bank because the water would gush out from behind them, although there was no
apparent backwards motion or floating debris…
