Understanding Water Resistance: A Guide for Your Watches

May 20, 2025

“Is my watch waterproof?” is a question we get asked frequently at WatchWorks. The short answer is yes and no. It depends entirely on your watch’s case construction, its crystal, the quality of the seals and gaskets, and whether you keep the screw-down crown tightened.

The term waterproof can be misleading, which is why we prefer water-resistant. A watch’s water resistance is measured by its ability to withstand a certain water pressure, often expressed in meters (m), feet (ft), or atmospheres (ATM). Misinterpreting these ratings can lead to irreversible damage — so it’s important to know exactly what your watch can handle.

How Water Resistance Works

Water resistance depends on several key factors:

Case construction

The strength and design of the case determines how well it keeps water out.

Seals and gaskets

High-quality seals prevent water from entering the watch.

Crown type

Screw-down crowns create a secure, watertight seal.

Crystal and case-back

The thickness and fit contribute to overall protection. Even a watch with a high rating can fail if the crown is unscrewed, gaskets are worn, or the watch has not been serviced regularly.

Water-Resistance Ratings Explained

Here’s a simple breakdown of common ratings and what activities they allow. The infographic below gives an easy visual reference for your watch’s rating.

Water Resistance Visual Table

Water Resistance	ATM / Depth	Recommended Use	Example Watches	Key Features / Visual Cue
30 meters	3 ATM / 100 ft	Splashes, rain, washing hands	Patek Philippe Calatrava, Cartier Tank	Light water protection only; do not swim or shower
50 meters	5 ATM / 165 ft	Splashes, rain, washing hands	Omega De Ville, some Cartier Santos	Slightly better protection; still avoid prolonged submersion
100–150 meters	10–15 ATM / 330–500 ft	Swimming, snorkeling, showering	Rolex Explorer I, Omega Seamaster Aqua Terra	Screw-down crown recommended; moderate water resistance
200 meters	20 ATM / 660 ft	Swimming, snorkeling, recreational diving	Rolex Submariner, Omega Seamaster Diver 300M	Thicker crystal; screw-down crown & case-back
300+ meters	30+ ATM / 1,000+ ft	Professional diving, skin & saturation diving	Rolex Sea-Dweller, Omega Planet Ocean	Helium escape valve; highly robust case; ideal for serious divers
Chronographs (no screw-down pushers)	Usually 50m	None – keep dry	Omega Speedmaster, some vintage chronographs	Do not swim or shower; especially important for vintage models

Quick Tips for Maintaining Water Resistance

✅ Always screw down crowns and pushers before water exposure.

✅ Service your watch annually; pressure-test vintage and dive watches.

✅ Avoid watches with cracked or damaged crystals in water.

✅ Be aware of thermal shocks (hot shower → cold pool).

✅ Replace worn gaskets to maintain full protection.

Why Water Resistance Matters

Understanding water-resistance ratings protects your watches from accidental damage and helps preserve their value. From a vintage Rolex to a modern Patek Philippe Nautilus, a Rolex Explorer I, or an Omega Seamaster Aqua Terra, knowing your watch’s limits ensures it stays safe in everyday life, on holiday, or underwater adventures.

At WatchWorks, all watches we sell, service, or restore are tested for water resistance according to the brand’s factory specifications, so your watches remain worry-free and ready for any occasion.