For many dive watch enthusiasts, it is essential to familiarize different terms involving diving timepieces. It is because not all functions and parts of dive watches are the same as other types of watches, such as the chronographs, pilot, or casual timepieces.

As tool watches, dive timepieces are unique and serve a purpose to divers. For one, it is mainly used for tracking the elapsed time underwater. It also provides the divers the accurate time to estimate ascend point while submerged in the water.

Here are some of the standard dive watch terminologies you should know.

Crown

The small knob on a watch has a variety of functions such as time and date adjustment and manual winding. It is made of metal and serves as a bridge between the inner and outside parts of the timepiece.  The standard watch crowns are either screw-down or pull/push.

Dial, Hands, and Indexes (Indices)

The dial contains the hands and indexes. Dial designs may range from simple to more intricate (like having moon phase, date window, or additional small dials). In addition, tool watches such as dive and pilot watches often have more complicated dials. For example, dive watches should technically have luminous dials, hands, and indexes to aid visibility underwater.

Glass

The watch glass covers the dial. It can be made of sapphire crystal, acrylic glass, or mineral glass. These three are the common materials used for watch glasses. The least expensive type of glass used is acrylic. It is robust, flexible, and transparent, but it is not scratch resistant. For designer watches, the mineral glass is often used because it is scratch-resistant. However, if you are looking for a more durable type of glass, using sapphire is a perfect choice. Although synthetic sapphire glasses are often used, its hardness makes it less prone to scratches and cracks.

Helium Escape Valve

The helium escape valve is a small spring that works when there is a change in pressure underwater to prevent the glass from cracking. When diving, there is excessive pressure underwater that may cause the watch glass to break during the ascend time. If your watch has an escape valve, you are assured that all the watch's pressure will be released.

Movement and Movement Type

The movement is the powerhouse of a watch. Without it, a watch cannot function. There are two types of movements: automatic or quartz. Both mechanisms are often used for diving watches these days.

Rotating Bezel

The most distinct part of a dive watch is the rotating bezel. This part is attached to the watch’s case and is mostly found only in diving timepieces. Bezels can move clockwise, counterclockwise, or both. It can be an internal or external bezel. The common bezel materials used in the watch industry are ceramic or aluminum rings.

Strap

The strap is an essential part of diving watches. There is no fixed and recommended strap for diving timepieces, although the most common are rubber, stainless steel bracelets, canvas, or NATO. What matters is that the strap should be durable, reliable, and can withstand water and humidity.

Super-LumiNova

The glowing property of a dial’s watch is possible because of certain luminous pigments. One of these is the Super-LumiNova, a brand name for strontium-based afterglow pigment used to illuminate markings on the numbers, dials, and hands. Other materials used for watch illumination are promethium and tritium.

Water Resistance

This is an essential characteristic of every timepiece, especially a dive watch. It is based on the industry’s standard ISO 6425. It is recommended to have a watch with at least 20 ATM resistance if you want to dive.