There’s a kind of wave in the ocean that can dwarf anything at Nazaré, home to what most people think of as the world’s biggest waves. You won’t see it break, won’t hear it roar, and you could sail straight over it without realizing a monster just passed beneath you. Welcome to the strange world of internal waves: enormous, nearly invisible swells that move through the ocean itself, rather than across its surface. In a recent video, narrator James Stewart describes the phenomenon (“some as tall as the Empire State Building”) that form between Taiwan and the Philippines before rolling across the South China Sea. Watch below, and learn more about these mysterious monsters. “From the surface, you would have no idea they were there,” he explains. “These are the largest waves produced in the world’s oceans, with up to 10,000 times the amount of turbulence typically found in the open ocean,” he continues.…