The date aperture clips off the large stylized hour numeral at 3 o’clock. Pride of place is given to the 24-hour window, which fills the bottom quarter of the dial. Ample luminous material on the hour and minutes hands, the hour indexes, and the bezel make the watch very readable in all light conditions.
The GMT Power-Reserve Chronometer uses Clerc’s C610 caliber. It’s an automatic movement that beats at 28,800 vph. It has 31 jewels and a standard power reserve of 42 hours. There is an exhibition caseback so you can see the movement at work. True to its name, the watch is a full-fledged chronometer, having been certified by COSC.
But the most notable features of the Hydroscaph are on its case. This is a big watch: although the diameter of the case is 43.8 mm, it ends up at 48 mm with its lateral reinforcements. In total, the case itself has 83 components. There is a helium release valve, seen on the case-side at 8 o’clock. The watch is water resistant to 800 meters.
The diving bezel is designed with Clerc styling, truncated to remove the edges that would stick up on a flat bezel. But it doesn’t turn manually. The dedicated crown at 10 o’clock keeps the bezel safely in its desired position; in order to rotate it, you have to release a flap on the bezel crown, then turn that bezel to the timing position you want.
The Hydroscaph GMT Power-Reserve Chronometer comes in three case versions: in stainless steel, in black DLC-coated stainless steel, and in rose gold with black DLC-coated steel. Dial variations are available in white, black, brown or midnight blue. It comes on a rubber strap with a folding clasp.