#Depth gauge watch iso#

Many bezels have only the first 15 minutes marked individually. Some watches solve this problem by using inner rotating bezels that cannot be rotated accidentally. Most dive bezels turn in one direction only, counterclockwise, so that the bezel cannot be accidentally knocked off position in the clockwise direction and thus understate the elapsed time (usually the total dive time) being measured. Why do the rotating bezels on most dive watches turn in only one direction? Some dive watches have a helium valve and/or a depth sensor.ДЄ helium valve prevents the watch crystal from popping off when the diver is in a decompression chamber. Some dive bracelets and straps are equipped with an extension device that enables the watch to fit over a dive-suit sleeve. Most dive watches have a steel or titanium bracelet or rubber strap, although some straps are made of nylon or various composite materials. A seconds hand satisfies this requirement.

#Depth gauge watch iso#

The ISO also says the watch must have an indicator that shows at a glance if the watch is still running. ISO standard 6425 requires a dive watch to have a вЂњtime-preselecting deviceвЂќ (a rotating bezel satisfies this requirement) and a dial that can be read in the dark at a distance of 25 cm. They also have luminous hands and markers that can be read underwater. Most dive watches have a rotating bezel for measuring elapsed time. What are the other features of a dive watch? Watches designed for very deep diving often have additional pressure-defying features such as domed crystals, or a steel ring for reinforcing the case (as on the Rolex Deepsea). The case and crystal are thicker than in a non-dive watch. O-rings are used to seal the crown, caseback and crystal.

In nearly all dive watches, the case has a screw-in back and crown. Several features are required to make a watch impermeable enough to wear diving. What features make a watch impermeable enough for diving? All these imponderables cause the companies to provide a rather large cushion of safety so that customers will not hold them responsible if their watches leak.ДЄ screw-in crown is essential to a watchвЂ™s water resistance. Knocks and other rough treatment can cause the caseвЂ™s components to fit together less tightly than they did when the watch was brand new. Furthermore, a watchвЂ™s water resistance will be lessened by aging of the watchвЂ™s gaskets. The testing machinery does not account for such phenomena as additional pressure from the impact of the wearerвЂ™s jumping or diving into the water or for temperature and pressure changes as the diver ascends and descends, which can cause the case to shrink or expand. For the test, the watch is perfectly stationary, the gaskets brand new, and the case newly assembled, so that nothing will compromise its water resistance. The reason for the discrepancy: when tested for water resistance in the factory, the watch is in an artificial environment that is much different from what the watch will face during an actual dive. Beyond that, they enter the realm of technical diving, which requires extensive training, special mixed gases to breathe, long decompression stops and special equipment.

Recreational divers donвЂ™t go deeper than 40 meters (130 feet). The International Standards Organization (ISO), on the other hand, stipulates that a dive watch must be water resistant to 100 meters.ДЄll these depth ratings are significantly higher (or lower, if you will) than the depths to which a non-professional diver can dive.

Others say the watch need have a rating of just 200 meters still others say it can be 200 meters as long as it is specifically labeled as a dive watch. Some manufacturers say that their watches with a water-resistance rating of 300 meters or more are suitable for recreational scuba diving. How water resistant should a dive watch be? We answer your FAQs about water resistance, dive bezels, depth gauges, and more about diversвЂ™ watches in this feature from the WatchTime archives.