Tides are caused by the gravitational interaction of the earth and the moon (and to a much lesser extent, the sun), causing periodic rises and falls of huge volumes of water.
- Two tides occur each day.
- Spring tides are strong tides, occurring when the earth, sun, and moon are in a line during a full or new moon.
- Neap tides are weak tides, occurring during quarter moons when the sun and moon are perpendicular to one another (with respect to the earth).
- Generally, the best time to dive is at high tide.