The Basics of the Rotating Bezel on a Diver Watch

Apr 14 2020 Journal

Understanding the operation of the rotating bezel is vital, especially for scuba diving, when it is used to measure the elapsed dive time. The unidirectional, ratcheting construction ensures that, should the bezel be accidentally moved, the time already spent underwater would be indicated as longer than actually spent, providing the diver with a safety reserve for his now more imminent ascent. It is important to stress that the bezel/minute hand combination does not directly measure how much air remains in the air tank.

Setting the bezel to calculate elapse time during dive

A typical sport scuba dive usually lasts 30 to 50 minutes, depending on the depth reached and the physical condition of the diver.

Before the diver’s descent, the 12 o’clock bezel marker is aligned with the minute hand, allowing the elapsed time, up to 60 minutes, to be read off the minutes marking on the bezel. For example, if your watch shows 4:30, rotate the 12 o’clock bezel triangle marker to align with the minutes hand to mark the start time. By reading off the bezel minutes marking would show the elapsed time.

Operating in Low Lighting

Indices and markers on a drive watch are coated with luminous paints to enhance legibility in poor lighting conditions, especially during diving at depth or on a night dive. This includes the “pearl” within the 12 o’clock triangular marker on the rotating bezel, which makes it highly distinguishable during operation.

Oris SA is renowned for producing mechanical watches at an excellent price-performance ratio. Oris offers an extensive range of Diving watches, highly regarded by the dive community and professionals alike. Check out the popular Oris Aquis Date (Ref: 733 7730 4157 MB) in 43.5mm stainless-steel case with 30 BAR Water Resistance.

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