If your watch says 30m, 50m, 100m or 200m water resistant, it can be tempting to take that number literally.
But water resistance is one of the most misunderstood features of a watch — and importantly, water resistant doesn’t mean waterproof.
Understanding the difference can help prevent an unexpected and potentially costly trip to the watch repairer.
Is any watch really waterproof?
In practical terms, watches are described as water resistant, not permanently waterproof.
Water resistance refers to a watch’s ability to withstand water under particular conditions and pressures. How much protection it provides depends on the design of the case, crown, crystal, seals and other components.
Those components can also change with age and wear.
A watch that was water resistant when it left the manufacturer isn’t guaranteed to maintain exactly the same protection indefinitely.
What do the water resistance numbers mean?
The depth rating on a watch relates to the pressure it has been designed and tested to withstand — but it shouldn’t automatically be interpreted as a safe diving depth.
As a general rule, a higher water-resistance rating provides greater protection, but always follow the manufacturer’s recommendations for your particular watch before swimming, diving or exposing it to water.
This is especially important with vintage watches, where age and previous repairs can affect the integrity of the case and seals.
Why does water resistance change?
A watch relies on seals and gaskets around areas such as the caseback, crown and crystal to help prevent water entering.
Over time, these can deteriorate.
Water resistance can also be affected by:
- Age and general wear
- Deteriorating seals or gaskets
- Damage to the crown or case
- An impact or knock
- Previous servicing or repairs
- Opening the case for a battery replacement
This is why you shouldn’t assume your watch is still water resistant simply because it was when you bought it.
What is watch pressure testing?
Pressure testing provides a way to assess whether a suitable watch is maintaining its expected water resistance.
It can be particularly worthwhile after the case has been opened, following repairs or battery replacement, or if you regularly wear your watch while swimming or around water.
And if you ever notice fogging or condensation beneath the crystal, have your watch assessed promptly. Moisture inside a watch can damage the movement, dial and other components.
Don’t leave water resistance to guesswork
Your watch may look perfectly sealed from the outside, but that doesn’t tell you what’s happening with the seals inside.
If you rely on your watch’s water resistance, periodic professional assessment and pressure testing can provide valuable peace of mind.
At JFP Watch Repairs, we provide watch pressure testing, battery replacement, servicing and repairs in Adelaide for suitable modern and vintage watches.