A whopping 94% of all life-forms on Earth are aquatic. Such a huge number of living beings who can't survive without water is understandable. After all, more than 70% of our planet's surface is covered with water. The World Ocean includes the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, and the Arctic Ocean. There's enough water in the oceans to fill a 685-mile-long bathtub! One of the main nagging questions people have been asking for ages is "How deep is the ocean in reality?" Let’s find an answer to it.