Requirements for a diver's watch
Requirements for a diver's watch are set out below.
> standard #1
water restistance ISO 2281
> standard #2
water resistance ISO 6425
[ ISO 2281 ]
-> water-resistant watches standard
- Resistance when immersed in water at a depth of 10 cm. Immersion of the watch in 10 cm of water for 1 hour.
- Resistance of operative parts. Immersion of the watch in 10 cm of water with a force of 5 N perpendicular to the crown and pusher buttons (if any) for 10 minutes.
- Condensation test. The watch shall be placed on a heated plate at a temperature between 40 °C and 45 °C until the watch has reached the temperature of the heated plate (in practice, a heating time of 10 minutes to 20 minutes, depending on the type of watch, will be sufficient). A drop of water, at a temperature between 18 °C and 25 °C shall be placed on the glass of the watch. After about 1 minute, the glass shall be wiped with a dry rag. Any watch which has condensation on the interior surface of the glass shall be eliminated.
- Resistance to different temperatures. Immersion of the watch in 10 cm of water at the following temperatures for 5 minutes each, 40 °C, 20 °C and 40 °C again, with the transition between temperatures not to exceed 1 minute. No evidence of water intrusion or condensation is allowed.
- Resistance to water overpressure. Immersion of the watch in a suitable pressure vessel and subjecting it within 1 minute to the rated pressure for 10 minutes, or to 2 bar in case where no additional indication is given. Then the overpressure is reduced to the ambient pressure within 1 minute. No evidence of water intrusion or condensation is allowed.
- Resistance to air overpressure. Exposing the watch to an overpressure of 2 bar. The watch shall show no air-flow exceeding 50 μg/min.
- No magnetic or shock resistance properties are required.
- No negative pressure test is required.
- No strap attachment test is required.
- No corrosion test is required.
[ ISO 6425 ]
-> divers' watches standard
- pressure resistant up to 20 bar or more
- the watch must remain two hours to a depth corresponding to the pressure specified by the manufacturer
- followed by several hours of stay in three meters deep
- means for preselecting a period of minutes and it deposed five-minute marks
- the preselected period of time and the second hand (or another function control) must be recognizable even in the dark
- the diver's watch must be antimagnetic according to DIN 8309: by magnetic influence of 4800 A / m the deviation may not exceed 30 seconds per day
- the diver's watch has to be shockproof according to DIN 8308: after a blow with 4.43 m / s the deviation must not exceed one minute at the day
- the diver's watch must survive without visible traces 24 hours in warm salt water
- during and after 20 minutes water pressure equivalent to the specified depth the diver's watch must still work
- the preselection of a period must still be operated in 30 centimeters of water depth
- the closed bracelet is charged for one minute at 40 kg, while nothing may loosen or bend
- the crown will be charged at 25 percent above the specified compressive strength ten minutes from the top with 0.5 kg, thereafter a condensation test
- in 30 centimeters of water depth, the watch is ten minutes 40 degrees Celsius, then ten minutes five degrees Celsius, then returned to ten minutes 40 degrees Celsius, thereafter a condensation test
- the diver's watch must for one hour 25 percent over a specified depth, then spend an hour at 0.3 bar vacuum, thereafter a condensation test
- Condensation test: This is done after each pressure test to determine the tightness of the case. This is heated to 40 degrees Celsius, then the glass is wetted with a drop of water. After dry wiping must show no condensation on the inside.
- while with a type test all the tests are done, the tightness must be made with 25 percent higher than a specified depth as an individual examination on each watch
- DIN 8306 is different from ISO 6425 requirements for accuracy: e.g. mean deviation between -4 to +6 seconds / day
[ Water resistance classification ]
Warter resistance rating |
Suitability |
Remarks |
Water Resistant 3 atm or 30 m |
Suitable for everyday use. Splash/rain resistant. Not suitable for showering, bathing, swimming, snorkelling, water related work and fishing. |
Not suitable for diving. |
Water Resistant 5 atm or 50 m |
Suitable for swimming, white water rafting, non-snorkeling water related work, and fishing. |
Not suitable for diving. |
Water Resistant 10 atm or 100 m |
Suitable for recreational surfing, swimming, snorkeling, sailing and water sports. |
Not suitable for diving. |
Water Resistant 20 atm or 200 m |
Suitable for professional marine activity, serious surface water sports and skin diving. |
Suitable for skin diving. |
Diver's 100 m |
Minimum ISO standard (ISO 6425) for scuba diving at depths not suitable for saturation diving. |
Diver's 100 m and 150 m watches are generally old(er) watches. |
Diver's 200 m or 300 m |
Suitable for scuba diving at depths not suitable for saturation diving. |
Typical ratings for contemporary diver's watches. |
Diver's 300+ m for mixed-gas diving |
Suitable for saturation diving (helium enriched environment). |
Watches designed for mixed-gas diving will have the DIVER’S WATCH xxx M FOR MIXED-GAS DIVING additional marking to point this out. |
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Water resistant mark shown on the pics below.
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