About a year ago, we published a guide that highlighted some of the most unusual complications we?ve come across. Among the parking meter timers, vibrating alarm watches, and altimeters, we featured depth gauge watches, which seek to combine two essential pieces of give gear into one device. Measuring depth using a pressure reading is simple enough, but becomes quite complex if you need to do it with a tool that can?t tolerate any water ingress whatsoever. Such is the unique challenge of a depth gauge watch. Lots of brands have made attempts at this over the years in different ways, but the Oris solution is unique in that it allows water to enter the watch in a controlled fashion. Announced today, the new Aquis Depth Gauge refines and improves the brand?s unique depth tracking solution. Let?s take a look. 
The Aquis Depth Gauge takes advantage of the scientific principle known as the Boyle-Mariotte Law, which describes how the pressure of a gas increases as the volume in a container decreases. The container in the case of the Aquis Depth Gauge is a thin channel that has been milled directly into the sapphire crystal. When the watch is topside, this channel is filled with air, but fills with water as it descends during a dive. As water gradually enters the channel as air leaves under increasing pressure, it creates the appearance of a ?watermark? where the air and water meet, which corresponds to a gauge running around the crystal that can be used to determine dep...