Waterproof watches: What bar, ATM and metre ratings really mean
Waterproof watches have long been a staple accessory for many people. Whether washing your hands, walking in the rain or swimming, the right watch can withstand it all without suffering any damage. But what exactly does ‘waterproof’ mean when it comes to watches? And how much water can a watch really withstand? This guide provides the most important facts and practical tips on the subject of water resistance in watches.
What does ‘waterproof’ mean in watches and why is the information often misleading?
At first glance, the term ‘waterproof’ sounds clear, but in the watch industry it is often somewhat misleading. For example, if a watch is labelled ‘waterproof to 50 metres’, this does not mean that you can dive to a depth of 50 metres with it without any problems. The specification refers to laboratory tests in which the watch is exposed to static water pressure for a short period of time without any movement. In real life, however, the watch is exposed to completely different pressures: when swimming, jumping or diving, movement and water pressure very quickly create significantly higher stresses than in laboratory tests. In addition, temperature differences, moving the crown or shocks can put additional strain on the watch's seals.
From the laboratory to reality: what the water resistance rating really means
To ensure that the water resistance of watches is comparable worldwide, all models are tested according to international standards – usually ISO 22810. Under controlled laboratory conditions, the watch is subjected to a specific test pressure, which is specified in bar or atmospheres (ATM). The terms bar and ATM are usually used synonymously, with 1 bar corresponding to approximately 1 ATM. The water resistance determined in this way indicates how much pressure the watch can withstand in the test.
The pressure value determined in the test is often converted into a corresponding water depth, which leads to the familiar specifications such as ‘water resistant to 50, 100 or 200 metres’. However, this metre specification is not equivalent to an actual diving depth and often leads to misunderstandings. Even swimming movements, jumping into the water or the water jet from a shower can briefly cause pressure peaks that significantly exceed the constant pressure applied in the laboratory test.
To provide reliable guidance on which watch is suitable for which specific activities, we have prepared a recommendation table:
- 3 bar / 3 ATM (30 metres): Protection against splashes when washing hands or rain, but not suitable for swimming or showering.
- 5 bar / 5 ATM (50 metres): Suitable for washing hands and bathing – but swimming, showering or diving are not recommended.
- 10 bar / 10 ATM (100 metres): Showering and swimming are possible, but prolonged diving is not recommended.
- 20 bar / 20 ATM (200 metres): These watches are suitable for diving in medium-depth water and can also withstand stronger pressure peaks.
- 30 bar / 30 ATM and above: Models with this level of water resistance are specially designed for recreational divers and professionals. They can also withstand great depths and extreme conditions.
How is a waterproof watch manufactured?
To ensure that a watch remains truly waterproof, all components must work together perfectly. The case is made from high-quality materials such as stainless steel and is manufactured with exceptional precision. Special rubber or silicone seals are used at critical points, such as between the case, glass and back. These prevent water from entering the movement. A screw-down crown provides additional security and is a must for sports and diving watches.
Carefree everyday wear: why a waterproof watch is worthwhile
Waterproof watches offer many practical advantages in everyday life and during special activities. They make life easier because you don't have to worry about rain, washing your hands or accidental immersion. They are particularly reliable when swimming, playing sports or travelling, protecting the movement from moisture and damage. Even spontaneous adventures (whether a trip to the beach, a canoe trip or simply a rain shower) become stress-free with a waterproof watch. In addition, the waterproof construction increases the longevity of the watch, as the sensitive inner workings are protected from corrosion and wear.
For long-lasting enjoyment: what to look for in a waterproof watch
Waterproof watches are practical and uncomplicated. Nevertheless, there are a few things you can do to keep them reliable for longer. Extreme temperature fluctuations, shocks or contact with certain chemicals such as soap, shampoo or chlorine can affect the seals over time. It is therefore advisable to rinse the watch with clean water after swimming or showering and to ensure that the crown is closed as tightly as possible when in contact with water. Having your watch checked regularly by a watchmaker can help to maintain its water resistance for many years.
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Watches from MIYEN MUNICH – water resistance that impresses in real life
Our watch models are water-resistant to depths of 100 to 200 metres, offering you reliable protection – whether in everyday life, while swimming or on adventures on and in the water. Thanks to high-quality materials, careful workmanship and screw-down crowns, our watches remain water-resistant and reliable even in demanding conditions. So you can always rely on your MIYEN MUNICH – no matter what the day brings.
