A whale shark, considered to be the planet’s biggest fish, was spotted off West Palm Beach, Florida, on April 9. Keith Brock and his wife went for a dive at a local spot called “The Trench,” when they encountered the animal.

Whale sharks can grow up to 40 feet long and weigh about 20 tons. They feed on plankton, krill and other small animals and are harmless to humans. They are classified as endangered.