Recommendations for diving watch maintenance and inspection. Proper after-sales maintenance for tools that tend to be overused.

Not only divers who use them in the harsh environment of diving, but even users who have no connection to diving tend to abuse diver's watches due to their high level of trust in their waterproof performance. But are there actually any correct maintenance intervals or handling methods specific to diver's watches?

How companies are making diver's watches last longer

　Many people wonder how many dives a diver's watch needs before it needs an overhaul. However, when writing this article, we contacted several manufacturers, but all of them simply replied, "It depends on the circumstances, so we can't say for sure." A watch's water resistance is guaranteed by a gasket that prevents water from seeping in through gaps in the case, but this is influenced by factors such as frequency of use and even daily storage conditions. Each manufacturer's response is understandable. So, in the absence of any guidelines, how should a diver's watch be cared for?

　In fact, the basic care is the same for both diver's watches and waterproof watches. No matter how waterproof a watch is, leaving sweat on it or storing it in a hot and humid place will still damage the gaskets. After use, you should wipe it with a dry towel and store it in a well-ventilated place. If you own a diver's watch and actually dive, you have no choice but to pay attention to how to prevent wear on the gaskets on a daily basis and perform regular maintenance.

Crown gasket, which is prone to wear

　Of all the gaskets used in watches, the crown is one that is most susceptible to wear depending on how the watch is used. This is because the crown is pulled out frequently to wind the mainspring, adjust the time and date, etc. To protect this gasket, which is prone to wear, Germany's Damasco has taken a unique approach. Their diver's watch, the DSUB1, uses a waterproofing mechanism known as a "gasket system" for the crown and pushers.

　This creates a space filled with lubricant between the two gaskets, reducing friction when they are pressed together. This naturally minimizes wear on the gaskets, as well. Additionally, in situations where water pressure is applied, the combined pressure of water and lubricant compresses the gaskets, ensuring water resistance even without screwing in the crown. This gasket system is also incorporated into the pushers, meaning the Damascus chronograph can be operated underwater.

Be careful with removable tubes

　There's one more area around the crown where maintenance is directly related to water resistance: the removable tube. In the past, diver's watches had brazed or welded tubes to prevent water from seeping in. However, as the quality of gaskets improved and became more consistent, removable tubes could still be used to achieve water resistance. Given that the tubes on the Rolex Oyster Perpetual Rolex Deepsea, which is water resistant to 3900 meters, are replaceable, there should be no issues with water resistance. The biggest benefit of having removable tubes is improved maintenance. If a tube is damaged, for example by hitting the watch against a rock, a welded one would require rewelding or, in the worst case, replacement, but a removable tube can be easily replaced.

　But does this mean that the benefits of a one-piece tube have disappeared? Not at all. The more gaskets there are, the greater the risk of water intrusion as the watch deteriorates over time. For this reason, many brands recognize that brazing is essential for the crown tubes of professional diver's watches. Citizen, one of the first to comply with the 2018 ISO 6425 standard, welds the tubes on all of its diver's watches.

　In addition, in Damascus, the base of the winding stem is movable to prevent damage to the tube when the crown is hit. This part breaks to absorb the impact. The crown protector used in Panerai's Luminor series also protects the crown itself from impact. It is thought that this mechanism was originally developed to avoid patents for screw-down crowns, but its advantages remain significant even now, approximately 80 years after its first appearance.

Maintaining the unidirectional rotating bezel

　The unidirectional rotating bezel, an essential part of a diver's watch, is also said to require regular maintenance. Whether it is a standard leaf spring type or the type used by Rolex, which uses ball bearings and stoppers, if dust, dirt, or sand from diving accumulates on the bezel, it will not rotate properly.

　Damasco's unidirectional rotating bezels are also very well thought out. Take the way the bezel is attached. While a typical rotating bezel is attached by press-fitting, Damasco rotating bezels, including the DSUB1 shown in the photo, are secured in place with a C-ring, regardless of the model. The C-ring fits into a groove on the dial side, and its protrusion then fits into a groove on the bezel side. This makes it less likely to come off due to impact than a press-fit bezel, and because this method allows for a gasket to be placed around the edge of the head, there is no need to worry about dust getting inside the bezel.

　Furthermore, the reverse rotation prevention mechanism does not use the classic leaf spring method, but instead uses ceramic ball bearings in three places and a single diagonally cut stopper. With the leaf spring method, the protrusions on the leaf spring catch on the grooves in the bezel to prevent reverse rotation, so the leaf spring itself wears out over many years of use. However, with the Damascus method, the ball bearing that rotates the bezel is made of ceramic, so it does not wear out. With this method, the only parts that wear out are the spring that moves the bearing and stopper in and out.

Maintenance is essential for diver's watches, which you entrust your life to.

　As you can see, even diver's watches are gradually becoming less frequent in terms of maintenance. However, if you don't always wash your watch with fresh water after diving, the stainless steel will corrode and the gaskets will deteriorate. Using a diver's watch for diving is essentially entrusting your life to the watch, so you can't afford for anything to happen. This is why it's essential to check the waterproofing before diving and to have it overhauled regularly. While there are special mechanisms that help extend the life of your watch, it's best to think of them merely as a way to reduce the likelihood of risks occurring while diving.