The Garmin Descent Mk3s is the compact 43mm model in Garmin's current flagship dive computer/smartwatch series, replacing the older Mk2s with a brighter AMOLED touchscreen and a deeper 200m dive rating. It runs the Bühlmann ZHL-16C decompression algorithm with user-configurable gradient factors, supports multiple technical and recreational dive modes, colour dive-view maps, and metal leak-proof buttons that stay fully operational at full depth — a meaningful step up in both display quality and dive-computer sophistication over the Mk2s. As an everyday smartwatch it carries over 100 built-in sports profiles, full health and training metrics, and Garmin's usual smart-notification and safety-tracking features. The 1.2" AMOLED display (390 x 390 px) sits behind a scratch-resistant sapphire lens in a passivated stainless-steel bezel, paired here with a Fog Gray silicone band on this AUS/NZ/Africa-region model. Battery life is up to 30 hours in dive mode and around 10 days in smartwatch mode. This is the pick for a diver who wants the newest Descent generation's brighter screen and deeper rating in a smaller case than the 51mm Mk3 — the equivalent 51mm model trades this compactness for a larger battery and longer runtime.