I ran accross this on another board and thought it would be good to share. I normally look for current predictions rather than tide when planning a trip. Although there are times when the tide plays a key role; such as when you want a little water under you when you're set up in the breakers waiting on a drum roll. Anyway I thought this gave a "little" perspective on what affects the tide and current.
Tides and Current
Tides and currents are two factors that have an enormous impact on saltwater and brackish water fishing in the Chesapeake Bay and along the coasts of Maryland and Virginia. Tides and currents occur throughout the region from the Atlantic Coast to the Chesapeake Bay, affecting bodies of water of every size and configuration.
Tides are complex movements of water that involve hundreds of variables. The most important element of tides is the movement of the moon around the Earth. The moon's gravity pulls water from place to place as it circles the planet. Twice each day, tides rise and fall in Maryland and Virginia.
Currents are caused by gravity, tides or the motion of bodies of water. In tidal water, currents may be nearly in phase with tides or may be offset by a considerable amount.
Saltwater - Freshwater Collisions
Often two or more bodies of water having different salinity levels collide. Although some mixing occurs, a certain amount of stratification (layering) may also occur. On the surface this may be very confusing to boaters and fishermen. Saltwater is heavier and tends to sink when it meets a body of freshwater. The result can make surface waters appear to be running "out" when in fact the tide is rising.
Temperature breaks occur when 2 currents collide. In the open ocean, this often results in eddies, also called gyres or ? These isolated bodies of water spin off from a parent current, sometimes travelling some distance before disbanding.
As wind move over a body of water, waves are created. This causes water on the surface to move in the direction of the wind. In some situations, wind blowing across a small waterway can cause surface waters to move in a circle or have an upwelling affect. Winds and the currents that result can have impacts on fishing. In the ocean and bay, water that is driven by the wind must be displaced, so the water from the below moves in to fill the void. The process continues which can dramatically impact water temperature, clarity, and other factors.