Imagine you’re invited to the beach, but you’re hesitant. Sure, it could be fun in the sun, but the thought of the vastness of the ocean makes you anxious. What could be out there in the waves?

The ocean floor is a vast scope on our planet that remains largely unexplored. Although oceans cover 71% of Earth, we have clearer pictures of the Moon and Mars than we do of the landscape beneath the ...

About nine million tons of visible plastic trash enter oceans each year—then there’s the waste we can’t see. This story appears in the May 2019 issue of National Geographic magazine.