Vast, powerful, beautiful, mysterious. For as essential as the oceans are to our lives and well-being, we know relatively little about them. In fact, we have better maps of the surface of Mars than we do of the oceans’ floors. While half of the world’s population lives within 40 miles of a coast, the rest of us need the oceans for climate regulation, transportation, food, fun, and even medicine.
In honor of World Oceans Day, founded in 2002, Instagram users are posting their favorite aquatic photos with the hashtag #NatGeoOceansDay. All day we’ll be updating this page as more submissions come in. Dive in!