The Submariner's rotatable bezel is a key functionality of the watch. Its 60-minute graduations allow a diver to accurately and safely monitor diving time and decompression stops. Manufactured by Rolex from a hard, corrosion-resistant ceramic, the Cerachrom bezel insert is virtually scratchproof. A luminescent capsule on the zero marker ensures legibility, no matter how dark the environment. The bezel’s knurled edge is carefully designed to offer excellent grip under water, even with gloves.