Paul Horsman

Seen from space, the earth is blue. That luminous blueness is water—the Atlantic, Pacific, Indian, Arctic, and Antarctic oceans. Seventy percent of what we call "earth" is under water. Life began in the ocean, and the ocean still plays a vital role in our lives and the earth's ecosystem. More than half the world's population lives within a few miles of the sea; we're drawn to it to swim, surf, sail, or simply gaze out across the waves.