Superman derives his powers from Earth's yellow sun, which saturates his Kryptonian cells with solar radiation. This energy conversion replaces conventional respiration under most conditions, granting him extraordinary durability and the ability to endure vacuum, extreme cold, and prolonged submersion without atmospheric oxygen.
Nevertheless, DC Comics writers have periodically imposed limitations on these abilities. Water-related vulnerabilities have emerged from pathogenic infections, magical effects, and narrative necessity. Each storyline approaches the question differently, creating a layered understanding of what happens when solar empowerment meets aquatic danger.