About The Watch ‘waterproof’ You Want To Know There Are

In the tabulation term, the word ‘Waterproof’ is very confusing. When and how to use a watch in water is a controversial issue. But obviously, some watches are more ‘Water-resistant’ than others. Generally speaking, dive meters can withstand water depths of 200 meters and above, even several kilometers (rarely). The performance of diving watches like this is rarely questioned, but the water resistance of other types of watches is hard to say.

   What is the practical significance of the numbers printed on the dial or case back? As Alexander Pope said, ‘knowledge is the most dangerous.’ The meaning of numbers is not only the depth level. When considering whether to take a risk, the number on the dial is only the most basic standard, and there are many other factors that are rarely discussed or understood to determine the water resistance of the watch.

Tudor Kai Cheng Biwan stainless steel watch for water resistance test

Battle of tags

   The most fundamental question is how to label water resistance. Some people insist that watches that are declared ‘water-resistant’ can only be used in water, and watches marked ‘water-resistant’ are only splash-proof. Strictly speaking, there are no technically ‘water-resistant’ watches today, nor are they allowed by international regulations. The logic is simple. Declaring ‘waterproof’ means completely immune to water. The International Organization for Standardization, the International Organization for Standardization (ISO), has set the standard for ‘Water-resistant Watches’ in ISO22810: 2010 (diving watches have separate ISO6425: 1996 standards).

   An important reason for using the term ‘water resistant’ is that the US Federal Trade Commission (FTC) has disabled ‘waterproofing’ because the latter is considered misleading. This goes back to a series of lawsuits against watchmakers in the 1960s, including the 1959 US Federal Trade Commission suing Waltham Watch Company. As the US Federal Trade Commission stated in 1999: ‘The word ‘Proof’ means absolute protection, but this does not exist in the case of a watch, and even more so in the long run.’

Tudor Case Seal Test

Key elements

   The water resistance of a watch is determined by three elements: the case structure, the mirror fit, and the integrity of the gasket. When the watch is assembled at the factory, all three elements determine its water resistance-but keep in mind that over time, as the watch is worn and worn, its performance will gradually decrease. In addition, watches are tested for water resistance during production, not when sold in stores, and may be months or even years away from the factory when sold. Then again, the watch is usually older after being returned for sale for the first time after 5 years of purchase.

   Compared to a 200-meter water-resistant diving watch, a 30- to 50-meter daily watch has fewer gaskets, a thinner mirror, and a lighter case. This does not mean that a 50-meter water-resistant watch is not suitable for swimming. It is really not appropriate to wear daily watches for scuba diving to extremely deep water. However, leisure swimming and even snorkeling, as long as they are properly maintained, will not affect The watch caused damage. There may be cases where the watch is worn by washing or immersing it in water, but the reason is not the depth level, but the quality of the watch.

Rolex Datejust Watch with Oyster Case

Technology & Quality

   In terms of water resistance technology, the standards and history of watchmaking brands are important, and Rolex is a good example. Even if the watches of different brands are printed with the same depth level, the manufacturing process and actual results are different. The Rolex Oyster (even the less sporty Datejust) has a water resistance rating of at least 100 meters, and the actual test standard is even higher.

   “Oyster” refers to the Twinlock double-locking screw-down crown. Usually the Rolex crown is decorated with two dots or a dash to indicate this structure (the Rolex diving watch is equipped with a triple-locking screw-down crown, and accordingly Crown decorated with three dots). The inner end of the crown is provided with a gasket, which is tight against the sleeve when screwed in to prevent water from the case. The sleeve itself is also provided with a washer, which is close to the arbor to protect the movement. This is the origin of the ‘double lock’.

   The ‘double lock’ has been tested repeatedly to guarantee the watch’s water resistance for a long time, because even if one of the gaskets fails, there is a second insurance. Generally, brands with a long history of diving watch manufacturing tend to perform more prominently. For example, GrandSeiko also equipped the case / crown sleeve with double washers.

   Most watch brands rely on a single washer construction, so although the marked depth levels are the same, it is difficult to remedy if they fail. A notable alternative solution is Panerai’s unique crown locking mechanism: leveraging the crown against the sleeve. This allows the crown to stay in place in the underwater environment, sealing the gasket. In this case, it functions the same as the screw-down crown.

Rolex crown and sleeve patent (US US5383166)

Actual situation

   In addition to intrinsic quality, the actual condition of the watch is also important. For example, how many times has the (quartz watch) battery been replaced? Who replaced it? Maybe the local watchmaker is not as professional as you think. In the simple process of battery replacement, the gasket may be improperly reinstalled or even damaged by the tip of the tweezers, making the depth level meaningless. Even if the watchmaker said that he tested the water resistance, considering his professionalism and the equipment he has, this sentence may not really be so credible.

   In addition to the lack of service, the role of time cannot be ignored. Over time, the tubular rubber gaskets become flat, brittle, and even chipped. At the same time, the gasket is also prone to wear due to friction, especially in the chronograph button. There are also some uncommon but more serious problems, such as the mirror surface cracking in the invisible place, the watch case deformed by impact, and the gasket can no longer function normally, resulting in leakage.

Rolex triple lock screw-down crown


   Improper operation may also cause water to enter the case. There may be many situations, but the end result is the same. The most common is that the crown is not tightened, and then the crown is pulled out during winding or setting. At this time, the gasket is not sealed.

   There is also missed regular maintenance. If you like to wear a watch for swimming, you need to regularly test the watch for water resistance every year. Although it is not necessary to perform maintenance, it can also prevent it. Testing is particularly important if the watch is damaged by a collision, and it is recommended to check it before re-use.

Automatic helium exhaust valve, suitable for watches in saturated diving environments, avoiding the risk of improper user operation

Hot shower

   There is a saying that moving in water will apply enough pressure to the watch, which will cause the case to crack, so a watch with a depth of 30 meters is only splash-proof. It is also false to say that a hot shower will damage the watch. The average temperature of the shower is 40 ° C. The rubber gasket in the watch can safely handle this temperature without distortion.

   Rubber gaskets are usually made of nitrile rubber or silicone resin. Nitrile rubber is still stable at temperatures up to 100 ° C, and silicone resin is much more than that. So even if the shower temperature is high, don’t worry too much. The same is true for mirror washers. These washers are usually made of compounds such as nylon or polytetrafluoroethylene (Teflon). They are also very resistant to temperature. The melting point of nylon exceeds 200 ° C. The melting point of Teflon 300 ° C.

   Soaps and harsh cleaning agents do have an adverse effect on watch washers, but that’s only in particularly high numbers.

Tudor Kai Cheng Biwan chronograph case with screw-in button


   Most chronographs, such as the OMEGA Speedmaster Moonwatch, have good water resistance. In a well-maintained condition, it’s no problem wearing a snorkel or even snorkeling in the shallows. The Speedmaster is equipped with a screw-down case and a solid crown washer. The resin mirror is fixed by a carefully designed tension ring. Each button is equipped with two washers.

   When the watch is immersed in water, operating the timer button is particularly prone to problems. In the static state, the presence of the gasket will create a sealed environment for the button, which is practical and effective; but once activated, the sealed environment no longer exists, and water may invade.

   Of course, some brands equip their watches with water-resistant buttons. Breitling’s Avengers Deep Dive Sea Wolf’s strategy is very interesting. It uses electromagnetic contact to operate the chronograph button to ensure an uncompromising tightness. The Omega Seamaster and some other mechanical chronographs can also be operated underwater. Omega does this with more washers, tighter tolerances, and a different approach to traditional button assembly.

   Keep in mind that chronographs with screw-in buttons, such as Rolex Daytona, should not be operated underwater. Whether a chronograph can be operated underwater, if in doubt, refer to the manufacturer’s instructions; if it is not clear, try to avoid it.

to sum up

   There are two main points about water resistance of a watch: the most important thing is maintenance, followed by full understanding and good habits.

   Maintenance means testing your watch for water resistance on a regular basis and replacing gaskets, buttons, crowns and sleeves as necessary. It’s also important to find a trusted watchmaker who should have the right equipment and know what he’s doing.

   Finally, pure depth grades do not guarantee water resistance. Depth ratings are only effective when the wearer uses the watch properly. (Photo / text watch home compiled by Xu Chaoyang)