The NATO Conversion

The North Atlantic Treaty Organization Conversion Watch is our latest tribute to American military timekeeping—this time with a twist in the timeline. At the heart of each piece is a rare Hamilton 3992B movement originally built for the U.S. Navy during World War II, later repurposed by the British Royal Navy, and upgraded in the 1970s by the North Atlantic Treaty Organization (NATO) with a special decimal dial used for time studies or what some call "work studies." These pocket watches were tools of precision and survival, used aboard naval vessels and in military labs to coordinate missions, navigate vast oceans, and conduct critical calculations in 1/100ths of minutes instead of seconds. At the heart of each piece is a rare Hamilton 3992B movement originally built for the U.S. Navy during World War II, later repurposed by the British Royal Navy and upgraded with a special decimal dial. These pocket watches were tools of precision and survival, used aboard naval vessels and in military labs to coordinate missions, navigate vast oceans, and conduct critical calculations. This is where form meets function. The restored white dial features dual timekeeping systems: an inner track of black hour numerals and an outer ring of red decimal minute markers, designed for quick mathematical conversions in high-pressure environments. Around the edge, traditional black numerals keep it grounded in familiar territory, while needle-tipped blued whip hands and a red sweeping seconds hand glide above the surface with clarity and intent. At the core is a 22-jewel Hamilton 3992B movement—fully rebuilt, visually stunning, and mechanically uncompromising. These movements feature a hacking function that stops the seconds hand when the crown is pulled, enabling military teams to synchronize watches to the second. Each movement is marked as U.S. government-issued and decorated with Geneva stripes, gold-plated gears, and fine-tuned for accuracy. Notice the 4 screws in the dial.... similar Colorado's GCT! We found these after we created the new GCT. Isn't that wild?! Encased in a 49mm Titankote ™ DLC-coated titanium case with a matching coin-edge bezel and knurled DLC crown, this piece is clean, rugged, and unmistakably military. Each customer receives both strap options: a black leather strap and a rugged olive NATO-style canvas strap—our first ever in this style—crafted exclusively for this project by Greg Stevens Design. Only eight will be made available. Once they’re gone, they’re history.