The south end of San Francisco Bay has a number of areas that are encircled with walls that allow the water to be cut off. These are used to dry out salt beds for harvesting. The sun evaporates the water and the salt is left when all the water is gone. After harvesting, the tide can be allowed to flood the beds again and the process repeated. One cool thing about these beds is that, presumably as a result of algae, they can turn some interesting colors as the water evaporates. I was flying in to SFO for work and we turned right over the beds on to the approach. With the sun out, the colors looked excellent.
The tide was very high when we got the parade in Cowes. The water level was just below the street level. Naturally, there was some swell, even though we were inside the harbor wall. This meant the water was pushing back up through the drains that normally take water from the street down to the sea. The water would force itself back up through the drains. Sometimes it was just a small amount of water but the bigger waves resulted in a bit more flow back out of the drain. Video is the best way to show this. The metal of the drain cover had the level of corrosion you would expect for something with this proximity to the sea!