Put your ocean knowledge to the test!

Let's start easy... World's Largest Ocean?

The ocean's cover how much of the Earth's surface?

The bottom of the ocean isn't just all flat -- there are ridges, columns and deep trenches. What is the deepest known area of the Earth's oceans?

Approximately how much of the oceans have us humans explored?

According to the United Nations, how many shipwrecks are there on the ocean floor?

What causes the oceans' tides?

The most drastic tides occur where in the world?