Tides

Although tides are best appreciated from a comfortable beach chair, truly understanding the motion in the ocean requires a trip to the moon. As you may have noticed, the moon is Earth’s only natural satellite, locked in orbit by the Earth’s gravitational pull. But the moon has a gravitational pull of it’s own, which tugs on the planet’s oceans; the water on Earth’s moon-facing side – or sublunar point – bulges out slightly, while the water on the opposite side – or antipodal point – is pulled slightly “in,” towards the Earth’s core.