In 1979, oceanographer Sylvia Earle descended 1,250 toes into the Pacific Ocean in a JIM swimsuit, setting the document for the deepest untethered stroll on the ocean flooring. Now, standing beside a duplicate of the enduring swimsuit on the new National Geographic Museum of Exploration, she shares what she skilled throughout that historic dive — and why the ocean continues to encourage marvel almost 5 a long time later, as half of the Rolex Perpetual Planet Initiative.