Reef 42.5

The Formex Reef 42.5 is a dive watch for enthusiasts who enjoy the engineering as much as the dial: its bezel and bracelet can be swapped without tools. That modularity gives it unusual flexibility, but the everyday attraction is simpler—a relatively slim case and a clasp that lets you fine-tune the fit as your wrist changes through the day.

The chronometer-certified Sellita SW300-1 is a familiar, thin automatic movement rather than an exotic proposition. When choosing between configurations, give the bracelet serious consideration: its quick-release attachment and on-the-fly adjustment are central to the Reef experience. The interchangeable bezel also deserves attention on a used example; make sure it seats securely and rotates positively after a change, and establish which bezel and attachment options actually come with the watch.