The sun and the moon affect not only the tides and ocean, they affect our everyday lives. The definition of tide is the rise and fall of water caused by gravitational forces of the moon and sun on the oceans of the earth. Generally speaking, tidal cycles contain two high tides and two low tides each day. During the time between high and low tide there will obviously be a current flow. When the sun is out the water tends to be very calm and flat unless there is a storm, but when there is a storm the sun goes away causing our waters to have very high tides, and that happens even more when the moon is out. If you're ever at a beach at night but you were there earlier during the day too, you'll notice that at night there are much bigger waves and a much stronger current. These are called neap tides and there is also spring tides that occur 2 times each month during a full moon.