You might want to know if your Seiko Watch is Waterproof? Will it survive rain? Can you shower with it? Can you jump in the pool? We'll answer all those questions, but to do that, we need to understand how watches are rated in "how well they can withstand water"

Seiko is known for producing durable, high-quality watches that perform well in various conditions, including exposure to water. However, like any watch, Seiko’s water-resistance capabilities depend on multiple factors, including water-resistance ratings (measured in ATM or “atmospheres”), maintenance, and age. Understanding these aspects helps ensure your Seiko watch remains protected from water damage.

Water-Resistance Ratings Explained: What 3 ATM, 5 ATM, 10 ATM, and 20 ATM Mean

Water-resistance ratings are crucial to understanding how a watch performs when exposed to water. Each ATM (atmosphere) rating indicates the level of water pressure a watch can withstand, where each ATM represents the equivalent of 10 meters of static water pressure.

  1. 3 ATM (30 Meters/100 Feet)
    Watches rated 3 ATM are resistant to minor water exposure, such as light rain or splashes during hand washing. However, they are not designed for submersion, swimming, or exposure to strong water jets. Despite the "30 meters" rating, this depth is misleading—it doesn't account for dynamic water pressure, such as moving your watch through water, which exerts far more force than a static depth.

  2. 5 ATM (50 Meters/165 Feet)
    A watch with a 5 ATM rating offers better water resistance than a 3 ATM watch. It can withstand splashes and brief immersion, such as during shallow swimming, but it’s not recommended for high-impact water sports or extended submersion. While 5 ATM can handle minor water exposure better, it is still best to avoid immersing it frequently.

  3. 10 ATM (100 Meters/330 Feet)
    At 10 ATM, Seiko watches can handle a broader range of water activities, including swimming, snorkeling, and surface water sports. A 10 ATM watch is significantly more resilient to water exposure and can manage moderate depths. This rating provides ample protection for those engaging in recreational water activities without the need for a specialized diver’s watch.

  4. 20 ATM (200 Meters/660 Feet)
    Watches with a 20 ATM rating or higher are suitable for serious water activities, including scuba diving, though not typically for deep-sea or saturation diving. Seiko’s diver watches often meet or exceed this rating, making them ideal for water sports enthusiasts and professional divers. With a 20 ATM rating, a Seiko watch can handle considerable underwater pressure, making it one of the most robust options for water resistance.

  5. Beyond 20 ATM
    Some Seiko models, particularly in their Prospex range, may offer water-resistance ratings of 30 ATM or more, designed for advanced or professional diving. These watches are rigorously tested for high water resistance, often featuring advanced seals and gaskets and undergoing pressure testing.

Additional Factors Affecting Water Resistance

While understanding the ATM rating is essential, several additional factors affect a Seiko watch’s waterproofness over time.

  1. Age of the Watch
    The age of a Seiko watch can have a direct impact on its water resistance. Over time, the seals, gaskets, and other components designed to keep water out can degrade, making the watch less waterproof. Older watches, even those with a higher ATM rating, may no longer meet their original specifications if these components have aged or worn out.

  2. Frequency of Maintenance and Servicing
    Regular maintenance, including servicing by a professional watchmaker, can extend the life of a Seiko watch’s water resistance. Routine servicing often includes checking and replacing seals, lubricating parts, and performing a pressure test. For watches used regularly in or around water, it’s generally recommended to have them serviced every one to two years to ensure that the water-resistance remains intact.

  3. Pressure Testing
    Pressure testing is an essential procedure to confirm a watch's water resistance. This test checks for any leaks and ensures the watch can withstand the rated water pressure. Pressure testing is recommended after any significant servicing, particularly if the watch case or seals were opened. For Seiko watches that frequently encounter water, regular pressure testing helps ensure they remain water-resistant over time.

  4. Condition of Seals and Gaskets
    Seals and gaskets are responsible for keeping water out, particularly around the crown, case back, and crystal. These components are usually made from rubber or silicone, which can deteriorate over time due to exposure to water, chemicals, and temperature changes. Regularly replacing these seals during servicing helps maintain the watch’s water resistance. Additionally, many Seiko dive watches feature screw-down crowns, a design that reinforces water resistance by forming a tighter seal.

Practical Tips for Maintaining Water Resistance in Seiko Watches

  1. Avoid Hot Water Exposure:
    While Seiko watches are designed to handle water, it’s generally best to avoid hot or chlorinated water, as heat and chemicals can compromise seals and gaskets.

  2. Rinse After Saltwater Exposure:
    Saltwater is particularly harsh on watches, so if you wear your Seiko in the ocean, rinse it with fresh water afterward to remove salt and prevent corrosion.

  3. Check the Crown Position:
    Always ensure that the crown is pushed in fully, or screwed down if applicable, before any water exposure. An open crown compromises water resistance, allowing water to enter the case.

  4. Regular Pressure Testing:
    Have your Seiko watch pressure-tested every year if you use it for water activities regularly. This test will confirm if the seals are still effective or if maintenance is needed.

How do I know if my Seiko Watch is Waterproof?

In most, if not all, situations, the ATM rating will be written on the caseback so that you can always verify how waterproof your Seiko Watch is. Seiko also uses badges, or logo's, to mark a specific water resistance / waterproof rating on the caseback.

3 ATM - no badge, text or markings? Your watch is 3 ATM!!

5 ATM - Single Wave

10 ATM - Double Wave 

20 ATM - On modern Seiko Diver's Watches, you will find the famous Seiko Prospex Wave. This means the watch is suitable for scuba diving, there is also non-scuba 20ATM rated Seiko's

Conclusion

Seiko offers a wide range of water-resistant watches with various ATM ratings to suit different needs, from casual splashes to deep diving. However, a watch’s water-resistance capabilities can change over time due to factors like age, maintenance frequency, and seal condition. Proper care, such as regular servicing and pressure testing, helps keep a Seiko watch in optimal condition for water resistance. With appropriate care and attention, a Seiko watch can provide reliable water resistance and maintain its durability for years.