Water Resistance Ratings Demystified: How the Screw-Down Crown Impacts Watch Performance

For watch enthusiasts and adventurers alike, water resistance is a critical factor when choosing the perfect timepiece. But what exactly do those water resistance ratings mean, and how does the screw-down crown play a role in a watch's performance underwater? In this blog post, we'll demystify water resistance ratings and explore the importance of the screw-down crown in ensuring your watch functions flawlessly in aquatic environments. 

Image from Spinnaker Watches

Understanding Water Resistance Ratings:

Water resistance ratings are typically indicated in meters (m) or feet (ft) and represent the depth to which a watch can safely withstand water pressure without sustaining damage. It's important to note that these ratings are based on ideal conditions and static pressure, so real-world performance may vary. Here are some common water resistance ratings: 


30m (100ft): Suitable for splashes, rain, and light handwashing. 

50m (165ft): Suitable for swimming and light water activities. 

100m (330ft): Suitable for recreational snorkeling. 

200m (660ft): Suitable for recreational scuba diving. 

300m (990ft) and higher: Suitable for professional diving and deep-sea exploration. 

The Role of the Screw-Down Crown:

The screw-down crown is a crucial component in achieving water resistance. It is typically found on the side of the watch case and is used to set the time and date. When the crown is in its normal position (unscrewed), it can be pulled out to adjust the time. However, in a screw-down crown system, turning and pressing the crown tightly against the case forms a watertight seal, preventing water from entering the watch's internals. 

Testing and Quality Assurance:

To ensure a watch's water resistance, it undergoes rigorous testing in controlled conditions. The screw-down crown is a focal point of these tests. Watchmakers simulate water pressure at the rated depth to check for any signs of water ingress. If a watch passes these tests, it receives a water resistance rating. 

Proper Usage and Maintenance:

To maintain the water resistance of your watch, it's essential to follow proper usage and maintenance guidelines. Always ensure the crown is screwed down tightly before submerging your watch in water. Additionally, have your watch inspected and serviced regularly by a professional to maintain its water resistance. 

Image from Spinnaker Watches

Water resistance ratings, along with the functionality of the screw-down crown, play a vital role in ensuring your watch can withstand aquatic environments. Whether you're a diver exploring the depths of the ocean or simply want a watch that can handle daily splashes, understanding these ratings and properly using the screw-down crown are essential for preserving your timepiece's performance and longevity. 


As you choose your next watch, consider your water-related activities and select a timepiece with an appropriate water resistance rating and a reliable screw-down crown mechanism. By doing so, you'll not only protect your investment but also ensure that your watch continues to tick accurately, both in and out of the water.