The ocean’s slow in-and-out breathing, driven by the Moon and Sun.

Why it matters: Tides shape beaches and schedule life for crabs, birds, and fish.

Fun Fact: Some places have mega-tides that rise and fall higher than a house!

Say it like this: TYDZ

Your turn: Tip a bowl of water gently, see “high tide” on one side, “low tide” on the other.