To maintain the watertightness of the watch provided with an inflatable reamer, it is necessary to proceed as follows:

Before performing the clock settings with the reamer, check whether the reamer is of the standard or inflatable type. The check is made as follows: in the position where the reamer is attached to the housing, turn it counterclockwise. If the reamer does not move away from the casing after rotation, it means that it is a standard reamer. If it moves away from the carcass following rotation (unwinding), it means that it is an infiltrable remontator.
Continue to unfasten the full reamer. Be careful not to force or abrade the reamer. When the reamer has been completely unfastened, pull it out slightly to the desired position for setting, then you must return it to its initial position by full flushing, that is, until it is fully glued to the casing without force.
Deviations of Quartz clocks with batteries can be within ± 15/20 seconds per month, and deviations of automatic / mechanical watches can be within ± 10/30 seconds per day. Water resistance is measured in bars (pressure unit, 1 bar being equivalent to 1 atmosphere) and watches are tested at these pressures for a certain amount of time. Extreme pressure, such as diving, may exceed these limits, so if you are a passionate diver, you will need a clock that tolerates such pressure.

Manufacturers often measure this water resistance at a number of feet (ft), meters (m) or atmospheres (atm). Watches marked "WATER RESISTANT" or "WR", with or without increased pressure indications, must be in accordance with NIHS 92-10 (according to international standard ISO 2281). Such watches are designed for everyday life and must be waterproof during exercise such as short-term swimming!

Diving watches must have a water resistance of at least 330 feet - approximately. 100 meters (this minimum value being valid for non-professional diving!). They must also have a time controller and comply with NIHS 92-11 (ISO 6425) standards: brightness, shock resistance, anti-magnetism, belt strength, etc.

The watertightness of the watches complies with DIN 8310 or ISO 2281. These standards describe the different water resistance categories as well as the test method used to determine water tightness. Except for models that do not have the "Water Resist" or WR (waterproof). These watches can not come into contact with water in any form!

In fact, water resistance according to DIN 8310 and ISO 2281 standards is not a permanent feature, as the gaskets are subject to the natural wear process. Extremely high or low temperatures, solvents and cosmetics can accelerate this process, and as a result, the gaskets become brittle and porous so that the product's tightness can not be guaranteed. Watches should be used within a reasonable range of temperatures, between + 10 ° C and + 40 ° C. (WARNING: Do not use hot / hot water - hot / hot water sponge, hot / hot shower, sauna etc)

Watches that have shown a certain resistance to water can not be directly used at that depth, as this is only the pressure at which the watch was tested. A clock is resistant to the influence of water on it at a specified static pressure (eg 10 BAR / ATM) and a theoretical water immersion at the specified depth.

Due to water movements, such as swim or water impacts, dynamic pressure may well exceed the specified static pressure and this may affect the watertightness of the clock when it enters the water!

Keep in mind that the value in meters does not refer to the depth of diving but to the air pressure used during the water resistance test !!!

What it is - (3 ATM (BAR) / 30 M *)
The watch has been tested for 3 ATM (BAR) pressure resistance, equivalent to the pressure applied by a 30-meter water column with a 1 cm2 section. Therefore, contact with water should be avoided, only resistant to minor splashes.

What is - (5 ATM (BAR) / 50 M *)
The watch was tested for resistance to 5 ATM pressure, equivalent to the pressure exerted by a 50-meter water column with the 1 cm2 section. Therefore, it is only suitable for use in routine activities such as showering or hand washing (WARNING! Do not use hot / hot water - hot / hot water hot water hot / hot water; sauna, etc)

What it is - (10 ATM (BAR) / 100 M *)
The watch was tested for resistance to a 10 ATM (BAR) equivalent the slow pressure exerted by a water column of 100 meters with the section of 1 cm2. That's why it's ideal for frequent swimming or snorkeling. (WARNING: Do not use hot / hot water - hot / hot water sponge, hot / hot shower, sauna etc)
What is - (20 ATM (BAR) / 200 M *)
The clock has been tested for resistance to a 20 ATM pressure (BAR), equivalent to the pressure exerted by a 200-meter water column with a 1 cm2 section. Therefore, it is ideal for immersion without equipment. (WARNING: Do not use hot / hot water - hot / hot water sponge, hot / hot shower, sauna etc)

* Indicator values do not refer to the depth of dive but to the pressure exerted during the leak test. (ISO 2281)