How deep is the ocean?

For the most part, the ocean’s floor is about 3.6 km below the surface of the water. However, there are extremely deep parts that reach far down into the water. The Mariana Trench, which lies in the Pacific Ocean close to the island of Guam, is the deepest of these trenches. It reaches a depth of about 11 km from the surface.

Mount Everest is the tallest mountain in the world at almost 9 km high when measured from sea level. The top of Mount Everest would remain below the surface of the water even if it were positioned on the ocean floor in the Mariana Trench.