Jure Malalan
Nejc Puš

On Water-Resistance

Jure Malalan
Nejc Puš

In the Malalan watchmaking workshop we often get wristwatches which due to gasket damage, often the result of blows or irregular maintenance, have had their water-resistance diminished or have even lost it. Many people are not aware of the importance of efficient water-resistance, nevertheless, water is one of the factors which can cause severe damage to or completely destroy the dial, hands, and the sensitive movement of a wristwatch.

Many people wonder why we cannot swim with a watch which is supposed to be water-resistant to, for example, 3 bars of water pressure.
Gaskets in the case of a watch

The movement is protected from external influences by the case and the greatest part of the surface where water can penetrate the interior of the watch are the two parts where the central case touches the glass and the caseback. The parts that are moved during the operation of the watch are also very exposed: the winding crown and the chronograph pushers. These are often screwed to the case to ensure the marked water-resistance.

Many people wonder why we cannot swim with a watch which is supposed to be water-resistant to, for example, 3 bars of water pressure. The answer demands an understanding of the basic laws of physics. In watchmaking factories and workshops the water-resistance test is performed with static pressure and even temperature, but when we jump into the sea the water suddenly hits the case. 

When we swim, we move through the water at a certain speed and so we often influence the wristwatch despite the small depth with a significantly higher pressure than 3 bars, which is generally measured at a depth of 30 meters.

Water-resistance marks and their meaning


No Mark
Water can penetrate the case even upon drizzle or light rain.
Water - Resistant

The case is protected from a small amount of water, the watch needs to be taken off the wrist when washing hands.

30 m / 3 bar

The watch can be worn when washing hands or showering, but not when swimming.

50 m / 5 bar

The watch can be worn when swimming but is not suitable for jumping into the water or diving.

100 m / 10 bar

The watch is suitable for snorkelling, but not for jumping into the water.

200 m / 20 bar

The watch is suitable for all water sports, except for diving where the air in the tank contains helium.

300 m / 30 bar

Watches that are water-resistant to 300 meters and more can be used also for saturation diving.

Submersion test at Malalan watchmaking workshop

When we swim, we move through the water at a certain speed and so we often influence the wristwatch despite the small depth with a significantly higher pressure than 3 bars, which is generally measured at a depth of 30 meters. The temperature expansion of materials should also not be neglected when, for example, we sink the case heated by the sun into the pleasantly cold seawater.


Therefore, outside laboratories the conditions are not ideal and when we add the human factor to the equation, the probability of water penetration into the case increases significantly. This problem can be caused by an incorrectly screwed-in crown, while another frequent reason is the damage done to the movable parts due to blows which change the fitting of the gasket and thus weaken their functioning. Another important factor with the gaskets is also time: with the years these become less flexible and consequently less efficient.


Outside laboratories the conditions are not ideal and when we add the human factor to the equation, the probability of water penetration into the case increases significantly.
Condensation test
Condensation test

For those who do not expose their timepieces to water, the aging of gaskets mostly only presents a potential threat, while those people who wear their watches constantly, even when swimming, can totally destroy their timepiece if they do not service it. Namely, after the salty water penetrates the case, the sensitive components of the movement can efficiently be repaired only a few days after the incident. Due to all this it is recommended, if only preventively, that you regularly check the state of the gaskets in the case of the wristwatch at official service outlets.


Ideally, those owners who expose their watch to water regularly, should have it checked at the official service centres once a year, prior to the swimming season. Thus, the affordable check-up avoids the demanding restoration of the oxidised movement or even the replacement of the entire timepiece. The preventive inspection of the wristwatch water-resistance consists of a dry test in the air chamber, after which the condition of the gaskets is checked: if they are hardened or cracked, they have to be replaced.

Every 5 years, when our watchmaking workshop performs the regular maintenance service of your timepiece, one of the most important procedures is to replace all the gaskets in the case and then systematically test the quality of the sealing with machines specially intended for this purpose. 

They simulate the influence of negative pressure on the empty case, the creation of condensation within the case due to temperature changes, and with professional watches also the sealing upon pressure comparable to several hundred meters of depth. 

Only when we are completely certain that the case is water-resistant according to the standards of the manufacturer, we replace the movement and guarantee its owner the appropriate water-resistance and see to it that the wristwatch is their companion upon every challenge.

Ideally, those owners who expose their watch to water regularly, should have it checked at the official service centres once a year, prior to the swimming season.
Disassembled Watch Case