I found an interesting site http://www.geo.arizona.edu/geo2xx/geo212/12/sld001.htm which describes many of the interesting features of tides both the common and unique aspects. As a Physical Oceanographer who spent many years studying tides and their effects on currents and coastal morphology, I have found that MOST people including very experienced watermen had little solid knowledge about tides. We were putting current meter moorings in a Florida inlet and the Capt.. of our workboat who is on the water every day, told us the flood current was very strong and that the tide must be at the top of the High tide. Was he correct? See below. We usually have some idea of what happens at our home port. But a more knowledge of tides requires both some physics and simultaneous observations at many locations to make sense. The site above gives very nice ( and correct) explanations of many of the mysteries of tides and currents. Here are some questions to test your knowledge. 1) Here in Miami we stroll the docks in November and see the high tide flooding the docks. In June the low tides expose bars that we never normally see. Why does this happen and what causes it? Hint; it is not the moon or sun. 2) During the periodic northeasters in New England down to Cape Hatteras we see coastal flooding and considerable damage to beaches and breakwaters. Why is the tide so high during these events? 3) You try to enter and inlet and the tide is in full flood. What is the height of the tide ( high tide , low tide, mid tide ) ? 4) Why is the tide once per day in the Gulf of Mexico and twice per day on the Atlantic coast of Florida very near by? Why do you always go shelling in Sanibel island at 6-7 AM ? Also, is twice a day really twice a day and is once per day really once per day. Hope this is interesting to you all. It will be interesting to see what the common knowledge is out there. Gregory Han ghan@GregHan.com