A diving bezel enables a diver to visually keep track of his/ her air supply by measuring dive time using minute markers from 0 to 60 on a unidirectional rotating bezel. Unidirectional bezels only rotate in the counter-clockwise direction for safety reasons. Before diving, the diver sets the bezel according to his/her air tank supply.

In many ways, shock resistance is even more important to a watch than water resistance. A wristwatch is subject to a lot of movement, sometimes sudden, and with a great deal of force. If a watch is not properly shock resistant, it is incredibly easy to impact the movement and damage it. There are several methods watchmakers use today to make movements shock resistant. One of the most common is the Incabloc system introduced by Universal Escapements, Ltd. of Switzerland in 1933. The Incabloc system allows the most sensitive parts of the movement to move sideways when impacted by a shock and then return to its normal position under pressure of small springs above the movable carriage. Most other shock resistant assemblies work off a similar principle to the Incabloc, using springs as shock ab

There are many different designs used for the hands of the watch. Hands that are a dark navy in color are called “blued steel” hands and are the result of super heating steel until the color changes. This technique was first used by the famous watchmaker Abraham-Louis Breguet in the 19th century to help make the hands more legible.

Many watches have glow-in-the dark hands and hour markers. The substance used for this purpose has evolved over the years. Originally, Radium was used in the 1950’s but was found to be highly radioactive and was replaced with a substance called Tritium. Tritium had much lower levels of radiotoxicity and was considered a much safer alternative to Radium. You can tell if a watch has Radium or Tritium markers because it will have the letter ‘T’ or ‘R’ printed on the dial, usually flanking the country of origin(ex. T-Swiss Made-T, or R-Swiss Made-R).

Recently a new substance, Super- LumiNova®, has been introduced, which has no radioactive properties and is three timesas bright as Tritium. It also does not discolor as Tritium does when it ages.

While not technically part of a watch’s anatomy, it is important to have a good understanding of what the phrase water resistance means and how it applies to a wristwatch. The term “waterproof” is not allowed by the Federal Trade Commission in the United States. This is because under the proper conditions, anything can leak. The phrase “waterproof” is used in almost all of the rest of the world.

A watch is generally considered water resistant if it can withstand the pressure of 30 meters (99 feet). Sometimes a watch’s water resistance is referred to in “atmospheres.” An atmosphere or “ATM” is 10 meters or 33 feet, therefore a watch that is water resistant to 3 ATMs is water resistant to 99 feet.

Bar

The Bar is a unit of pressure measurement that is essentially equivalent to an ATM. If a watch displays that it is pressure resistant to 3 Bar, it would be water resistant to 99 feet.

A diving bezel enables a diver to visually keep track of his/ her air supply by measuring dive time using minute markers from 0 to 60 on a unidirectional rotating bezel. Unidirectional bezels only rotate in the counter-clockwise direction for safety reasons. Before diving, the diver sets the bezel according to his/her air tank supply.

Many professional dive watches are equipped with a helium escape valve, a watch feature geared towards professional deep sea divers. It allows the extreme pressure from the depths of the sea to escape the watch via a valve that automatically opens when the pressure is greater inside the watch than outside.

Leather strap attached to folding metal buckle that is considered safer to wear than a regular Ardillon buckle due to the fact that if the buckle should open up, the watch is still attached to the wrist. This was invented by Louis-Cartier in the early 20th century.