Editor’s Note (10/4/18): Brazilian surfer Maya Gabeira has set the world record for the biggest wave ever ridden by a woman—a 68-foot giant along the coast of Portugal—confirmed by Guinness World Records. In August we published the article below, explaining how these monster waves form, and how champion surfers like Gabeira and the male record holder, Rodrigo Koxa, figure out how to ride (and survive) them.