Dive into Excellence: Conquer the 2026 NAUI Open Water E-learning Challenge!

Refraction at the water–air interface in a diver’s mask makes underwater objects look larger and closer. Light travels from water into the air in front of your eye and bends away from the normal, altering the path of the rays so they reach your eye as if they came from a point nearer than the actual object and spread out a bit more. The mask’s air gap acts like a magnifying lens, increasing the apparent size and shrinking the perceived distance. That’s why things look bigger and nearer when you’re looking through a mask.