The Alpina Seastrong Diver 300 Chronograph Big Date is a professional diving watch. Everything about this model is designed to handle the most extreme conditions, starting with water resistance to no less than 300m/100ft.
The aluminum, unidirectional, turning bezel, turns in just one direction: anti-clockwise. With this “fail-safe” feature the number of elapsed minutes can never be accidentally decreased, only increased. In addition, the 60 minutes markers on the black bezel are luminous, as are the dial indexes, which perfectly contrast against the matt black dial. The watch’s hands are luminous for maximum readability in low visibility conditions, and the minute’s hand is oversized to instantly read diving time.
Built-in features that are relevant to the professional diver include a 44 mm black PVD coated, cushion shaped, stainless steel case, screw-in crown and case-back, a scratch-resistant sapphire crystal and a black water-resistant rubber strap.