Benthos

The Aquastar Benthos made waves in the late 1960s as one of the first professional dive watches to feature a built-in chronograph, purpose-built for commercial and military divers tackling deep-water missions. Its distinctive single-pusher chronograph and internal rotating bezel set it apart from contemporaries, while the cushion-shaped 42mm case delivers unmistakable vintage tool watch presence. Collectors value the Benthos for its genuine diving pedigree and its role in advancing underwater chronograph design.

Key references include the Benthos 500 and Benthos I, which differ in movement and depth rating. The Benthos 500 houses a Valjoux 7750-based automatic chronograph and is rated to 500 meters, while earlier Benthos I models use a manual-wind movement with a 200-meter rating. Dial variations, condition of the original bakelite bezel, and the presence of the correct signed crown all drive price differences. Authenticity is best assessed by examining the unique caseback engravings and the one-minute chronograph hand, a feature specific to this model.

Prices for the Benthos fluctuate based on originality, with untouched dials and bezels commanding premiums. Service parts—especially crowns and bezels—are scarce, so examples with all period-correct components are especially desirable. The Benthos is an excellent choice for collectors seeking a historically significant Swiss dive chronograph that stands apart from the mainstream, but patience is key: well-preserved examples surface infrequently.