Take "The End" back. So tides are under the influence of the sun and the moon... the moon is closer, therefor has more gravitational pull. The sun is farther away, so it has less pull...
Oh, and Neap tides are smaller (because the sun and moon are pulling in opposite directions) while Spring tides are larger because the moon and sun are pulling in the same direction.
Current:
There are shallow currents (influenced by land masses and winds) and are used by ships to sail around the world. The shallow currents are circular, and in a specific area (separated by land mass). The currents spin; clockwise in the Northern Hemisphere, and counterclockwise in the Southern Hemisphere. There is not current in the equator... called a doldrum.
There are also deep currents (aka thermohaline) (influenced by salt and temperature) which is all the water in the world. Heard of "Global Conveyor Belt"? Yeah, that has to do with deep currents. In this, the cold water (as usual) sinks, along with the salt water (as usual) (hot water goes up, then cools down, then sinks...)
There is the Hadley Cell, where at the Equator, hot air goes up, then goes down. Coriolis Effect makes the it that when the hot air goes up, then goes down, it does not come back in the same place. This then makes little loops around the equator.
