On a return trip from Waikato, we stopped at Mokau for a bit of fish and chips at the beach before our last bit of journey home. As we watched the tide and the waves (and from a warning sign for swimmers and surfers), we realized that there was an interesting rip tide that kept sweeping past us from right to left. It looked like someone was pulling a toy on a string straight across our path causing the water to spray upward. Click on the top picture to see it more vividly.
Just a bit to the left of where the first photo was taken, we noticed that there were two sets of waves moving in perpendicular directions. This was due to the river feeding from the extreme left. It made an interesting pattern on the water's surface.