The Oris Depth Gauge is a professional diver's watch with an ingenious depth gauge. In fact, Oris engineers have engraved a thin channel on one side of the sapphire crystal. This channel runs counterclockwise around the crystal and terminates between the 1 and 2 o'clock markers. A valve, then positioned at 12 o'clock, creates the connection to the channel. When diving underwater, water enters the engraved channel through the aforementioned valve, and the resulting increase in water pressure compresses the air inside the channel. The water itself changes the colour of the channel to dark grey. The boundary between dark grey (water) and light grey (compressed air) indicates the depth on the yellow metre scale inside the sapphire crystal. The latter, which is 50% thicker than average, is domed and anti-reflective. The Oris Aquis Depth Gauge has a 46 millimetre diameter steel case, is water-resistant to a pressure of 50 atmospheres and is powered by a self-winding mechanical movement, Oris calibre 733 (based on the Sellita SW 200), while the unidirectional rotating bezel has a ceramic insert. Combined with a rubber strap equipped with a slide to quickly adjust its length, it is sold at a price of €2,600.
