Yesterday, during low tide most of the reef was exposed to the winds and small waves. While low tides often do reveal the areas closest to the shore, this was one of the first times that a great amount of the reef was above water. Tides are controlled by "tidal forces" which is an effect of the pull of gravity. Because of Newton's universal law of gravity, the moon and the sun exert a certain amount of force upon the Earth and the particles of the water. The ocean changes according to the changes in the distance between the two bodies (r).