There are particular features that set divers watches apart from other watches.
The standards for what exactly constitutes a divers watch is regulated and defined by ISO-6425 – this is the international standard for divers watches. Only watches that are officially, formally and technically ISO-6425 certified, are considered to be full-fledged divers watches.
In order for a watch to be qualified to be called a divers watch, the watch needs to be water resistant down to 330 feet/100 meters minimum.
According to the ISO-6425 international standard, divers watches are tested under 125% of the formally and officially rated water pressure. This means that if a divers watch has a 200 meter rating, it has to withstand a water pressure of 250 meters, and if a divers watch has a 300 meter rating, it has to withstand a water pressure of 375 meters. The water resistance is measured in feet (ft), meters (m) or bars (bar).
Time Controller And Additional Functions:
A divers watch must also feature a time controller – usually a unidirectional bezel with which you can measure for how many minutes you’ve been under water. The indexes of the dial must be luminescent in the dark, and the timepiece must have a solid band, anti-magnetic properties and shock resistance.