[davidpm]

http://i.imgur.com/1kqO3Tm.gif

 

[TakeFive]

This graphic can depict much more than wave traveling in open waters. It also give a rough depiction of how waves propagate up a river. When driven by the gravity-induced tidal rising and falling of the oceans, this wave propagation leads to tides and tidal currents far upstream in a river. By focusing on the surface dots, you can see clearly that there are times when the tide is rising even though the current is ebbing. Likewise, there are times when the tide is falling even though the current is flooding. In other words, tides and tidal currents are out of phase, with slack water often lagging the tidal extrema by a significant amount.

 

[RichH]

Very interesting graphic.

Think of the wave mechanics during a broach while youre 'stuffed' down and heeled over in the trough .... and that higher surface velocity from the oncoming wave peak impacts your stern .... and now the ass-end of the boat wants to go faster than the rest of the boat.
Easy to see 'why' in that graphic.

Thanx for posting.