Tides are primarily driven by the gravitational forces of the sun and the moon. Low tide, when the water is lowest at the location of interest, occurs at different times in different locations. As the moon orbits earth, its gravitational force pulls on the oceans, raising the water level.
Long waves are pulled by the gravity of the sun and moon. These waves travel around the world’s oceans and can reach over 50 feet in extreme cases. Locations may experience one or two low tides a day. In the case of two low tides a day, the tides may be approximately the same height or vary considerably.
Other factors that can influence tides include: the overall ocean wave patterns, barometric pressure and the shape of the ocean floor leading to the location. King tides, also called spring tides, occur in the northern hemisphere during December and January when the moon and the sun are in perfect alignment and mark the widest range between the high and low tides.
Tides can be observed with a video camera or stop lapse photography recording a shore line over the period of a day. Tide charts are available for many areas detailing the high and low tide heights as well as the time of day they occur in a given location. These tide charts can be very useful for fishermen as well as beach goers.