Divers Watches-Water Proof Not Just Water Resistant
Divers watches allow you to dive to depths in seawater environments. Watches rated for diving must pass the ISO (International Organization for Standardization) test 6425, to qualify as certified dive watches. ISO also prohibit the term “waterproof” being used on non-dive watches, watchmakers must instead rate their watches as “Water Resistant” and pass the ISO 2281 test. The vast majority of sports watches are in this category, that is they are fine for swimming and recreational use in water, but unlike a dive watch will hold up under the extreme pressures associated with scuba diving.
The ISO 6425 that all dive watches must pass requires watchmakers to subject their watches to a series of robustness tests. In terms of depth rating, a divers watch is actually tested to 125% of it’s rated pressure rating, so a 300m dive watch has been tested to depths of 375 meters.
The specific water resistance testing, ISO 6425 entails consists of:
– Fifty hours of immersion in 30 cm of water
– Ten minutes under 125% of rated pressure (plus a force of 5N perpendicular to the crown or any pusher buttons)
– Subjection to temperatures of 40 degrees C for five minutes, 5 degrees C for five minutes, then 40 degrees C again (immersed in 30cm of water – change between temperatures does not exceed 1 minute)
– Two hours of immersion in a pressure vessel at 125% of rated pressure with no evidence of condensation or water intrusion.
(pressure applied within 1 minute – over pressure reduced to 0.3 bar with one minute and maintained for one hour)
Mixed gas diving requires the watch to be immersed in a suitable pressure vessel in a helium enriched breathing gas mix and then tested at 125% of rated pressure for a period of fifteen days. No intrusion of water or condensation must be observed – over pressure is reduced to normal pressure with a three-minute period.
Dive watches are the most thoroughly tested sports watches. Even if you don’t wish to dive regularly (or at all) with your watch, purchasing a diver watches offers you some assurance that your watch will last a long time and hold well up to stringent environments in extreme circumstances. In other words you could consider a divers watch among the toughest sports watches on the planet!
For much more information on divers watches visit our website Sports Watch Informant.