Answer: This is an exaggeration. If you bleed in the water, sharks won’t come after you from across the ocean. Sharks have a large area of the brain dedicated to smell, allowing some of them to detect one part of blood in 10 billion parts of water—about one drop in an Olympic-sized pool. However, the ocean is vast, and it takes time for scent molecules to travel. On a good day with favorable currents, sharks might be able to smell their prey from a distance of a few football fields—not miles away
