Nivada Grenchen Chronomaster Aviator Sea Diver 105 / 9855

This reference marks the third and final generation of the vintage Chronomaster lineage, representing a radical modernization to align with late 1970s tastes. The most significant change is the adoption of the legendary Valjoux 7750 automatic chronograph movement, replacing the manual-wind calibers of all predecessors. This upgrade also introduced a day-date complication, displayed at the 3 o’clock position. The case design was completely overhauled into a large, 42mm cushion or tonneau shape with integrated-style lugs, giving it a much heavier wrist presence. Reflecting this modernization, the “Aviator Sea Diver” moniker was dropped from the dial, which was typically branded simply “Nivada Automatic”. The dial layout was configured to the Valjoux 7750’s signature 12-6-9 subdial arrangement, and the versatile rotating bezel was often replaced with a fixed tachymeter scale, pivoting the watch’s identity from a multi-purpose tool watch to a modern automatic motorsports chronograph.