ReviewOris Aquis Depth Gauge: A Watch That Allows Water Inside

Water is the enemy of mechanical instruments. The fine, intricate machinery inside a mechanical or quartz watch can be completely spoiled by water. For centuries, watchmakers have gone to great lengths to prevent water entering the case of a watch. Millions of dollars and countless hours have been spent researching means of making wristwatches water resistant. This is especially significant in diving watches, where the need to keep water out of the watch is even more important. Professional diving watches boast of their capacity to keep water from entering their case. But then, here comes a diving instrument that completely changes all the rules. It‘s called the Oris Aquis Depth Gauge.

The engineers at Oris have not only found a way to welcome water inside a watch, but also ingeniously found a mechanism to use the water to effectively measure depth underwater. The sapphire crystal of the Aquis Depth Gauge has a hole at 12 o’clock from where water is actually allowed to enter into a milled channel. As the water enters the channel, it compresses the air inside causing a change in the colour of the channel and thus indicating the depth underwater. The entire system is based on a law of physics called Boyle’s Law. Surprisingly, this isn’t a new discovery in physics. Boyle’s Law was first published more than 300 years ago in 1662 and is now part of the standard curriculum in 11^th grade physics. Oris is the first watchmaker in the world to recognize the application of this simple law in watchmaking. The invention was patented by Oris in 2012.

To put it in very simple terms, Boyle’s Law states that if a gas’s volume is decreased, its pressure increases proportionately. In the case of the Aquis Depth Gauge, the pressure of the water entering the milled channel in the sapphire crystal decreases the volume of the air inside it, thus compressing it. The point where the compressed air meets the water marks the depth underwater on a scale on the outer rim of the dial. It’s an inspired solution to an age-old problem. Most diving watches with a depth gauge use a pressure membrane, but the Oris Aquis Depth Gauge uses a material that is abundantly available in the ocean: water.

Oris has a great deal of experience producing professional diving watches, especially the ProDiver series, and hence the expertise shows in the Aquis Depth Gauge as well. The timepiece has all the standard features you would expect from a great dive watch, the most important of which is a water resistance of 500 metres. The stainless steel case is quite large, with a diameter of 46 mm, ensuring excellent legibility underwater. The black dial is clean with thick hour and minute hands along with a running seconds hand in a distinctive silver-tone. The hands and indices have been coated with Super-LumiNova for enhanced visibility in the dark. As for the sapphire crystal, it has been coated with anti-reflective treatment for perfect readability in the harsh glare of the sunlight as well as underwater. A date display window is located at 6 o’clock and the depth gauge scale in yellow is located on the outer rim of the dial in anti-clockwise direction. The ceramic bezel is a unidirectional rotating one, for measuring time underwater.

The watch is equipped with a black rubber strap that features a special clasp with a “sliding sledge” that allows one to quickly adjust the length of the strap without having to open the clasp. The package of the watch also includes an additional multi-piece links bracelet of stainless steel along with a set of tools to change the strap. This entire set comes within a case which is also water resistant.

The Oris Aquis Depth Gauge is not only an excellent diving watch, but also an innovation in dive technology. It is the world’s first watch that allows water to enter inside it, and also uses the water to measure depth underwater. The Aquis Depth Gauge from Oris is the perfect addition to the collections of those who have a passion for watches and appreciate fine works of engineering.