Water resistance ratings are based on controlled lab pressure tests, not real-life conditions.
When a watch says it’s water-resistant to 50 meters most people assume that means they can swim 50 meters underwater, but that’s not how it works. Water resistance ratings are measured under static lab pressure, not real-world conditions. In everyday use, movement, heat, and water impact create much greater stress than what’s simulated in testing.
Here’s what those numbers actually mean in practice:
It’s also important to remember that water resistance isn’t permanent. Over time, gaskets dry out, seals wear, and even a strong watch can lose its protection. That’s why brands like Rolex recommend having your water resistance tested every few years, especially if you wear the watch in or around water.
In short, think of water resistance ratings as guidelines, not guarantees. A 100m watch is great for the pool, but if you’re diving, or just want peace of mind, make sure your watch is recently pressure tested (or under warranty) and your crown is always screwed down.
