What features must a diver's watch have?
Anyone interested in diver's watches will sooner or later come across the term "ISO 6425". But what exactly is behind it, and what does it mean when a watch is sold as an ISO-certified diver's watch? Here you will find a clear overview of the most important requirements of the ISO 6425 standard.
Water Resistance
The minimum requirement for a certified diver's watch is water resistance of at least 100 meters (10 bar). In fact, every watch is tested for pressure resistance 25% higher than specified to ensure additional safety.
Good Legibility
A diver's watch must be clearly legible underwater, even in poor lighting conditions. This includes clearly visible luminous markers on the dial and hands. In particular, the minute hand must be easily distinguishable and recognizable at all times.
Unidirectional Rotating Bezel
An essential safety feature is the unidirectional rotating bezel with minute markers. It is used to monitor dive time and prevents accidental adjustments that could extend the dive time.
Function Indicator
To check proper operation at any time, a diver's watch must have a running seconds hand or a comparable function indicator.
Resistance to Magnetic Fields
Diver's watches must withstand a magnetic field strength of at least 4,800 A/m to prevent timing inaccuracies or stoppages due to magnetic influences.
Shock and Saltwater Resistance
A diver's watch according to ISO 6425 is robust and must be permanently resistant to both mechanical shocks (ISO 1413) and saltwater.
Temperature Resistance
The watches must function under various conditions, from at least 5 °C up to a maximum of 40 °C.
Condensation Test
A condensation test ensures that no moisture forms inside the watch that could cause damage.
Durable Crown and Strap
The mechanical strength and water resistance of the crown and operating elements, as well as a robust strap, are also required.
Conclusion
The ISO 6425 standard defines clear and strict criteria that a true diver's watch must meet. Anyone who purchases a watch with this certificate can be confident of having a reliable instrument for all diving adventures on their wrist.