A bezel is the ring surrounding the watch face, which can be fixed, rotating for functionality like timing, fluted for decorative purposes, or made of ceramic for durability and scratch resistance.
The bezel is the ring surrounding the watch crystal (glass) that holds it in place against the case. Beyond this structural function, bezels serve decorative and functional roles: dive watch bezels have elapsed-time markings, tachymeter bezels measure speed, GMT bezels track a second time zone. Bezels can be fixed, unidirectional rotating, or bidirectional rotating depending on their function.
Dive watch bezels rotate only counterclockwise as a critical safety feature. A diver sets the bezel's zero marker at the minute hand when descending to track elapsed dive time. If the bezel is accidentally knocked during the dive, it can only rotate counterclockwise, making the elapsed time appear longer than it is—causing the diver to surface earlier than necessary. A bidirectional accidental knock could show less time elapsed, potentially causing dangerous overstays.
Stainless steel bezels are most common, available in polished or brushed finishes. Ceramic bezels (found on modern Rolex Submariner, GMT-Master II, and Omega Seamaster) offer extreme scratch resistance and deep, stable color that doesn't fade. Aluminum bezels (used on vintage dive watches) show more wear character over time. Gold, platinum, and diamond-set bezels appear on dress and jewelry watches. Hardened sapphire crystal bezels offer maximum scratch immunity.