Answer
How often should a watch be pressure tested?
Short answer
About once a year if the watch goes in water, and always after the case has been opened for a battery, a service or a caseback engraving. A watch that never gets wet can wait for its next full service. A dry test takes a watchmaker a few minutes and typically costs roughly $25 to $60 before sales tax, with local bench rates moving the figure.
On this page (4 sections)
Roughly once a year if the watch goes in water, and immediately after any case opening. That is the whole schedule. A watch that lives on a desk and never sees more than rain can reasonably wait for its next full service, because the seals age slowly when nothing heats, soaks or disturbs them.
The reason the test exists is simple. The number on your dial describes the watch as it was manufactured, under a static pressure test at room temperature, on a case whose gaskets had never been compressed for years, heated in a shower or smeared with sunscreen. Only a pressure test describes the watch you actually own today.
The schedule, by how you use the watch
| How you use the watch | Test interval | Why |
|---|---|---|
| Swimming, ocean, pool, showering in it | Annually | Seals face heat, chlorine, salt and repeated pressure cycles. Failure is a matter of when. |
| Certified divers' watch used for diving | Annually, before the season | The watch is safety equipment. Test it before a trip, not after one. |
| Everyday wear, occasional splash | Every two to three years | Enough to catch an aging gasket before rain and handwashing find it. |
| Dress watch that never gets wet | At the next full service | Nothing is stressing the seals, and the watch is not asked to keep water out. |
| Any watch whose case has just been opened | Before it gets wet again | A battery change, caseback engraving or movement service disturbs every seal in the chain. |
| Vintage watch of any kind | Test, then assume the answer is no | Original gaskets are decades past their service life, and case tolerances have often been altered by polishing. |
Dry test versus wet test
There are two bench methods, and they are not interchangeable.
A dry test seals the watch in a chamber and applies air pressure while a sensor measures how much the case flexes. A sound case deforms slightly under pressure and springs back when the pressure is released. A case that has let air in past a bad seal does not return the same way, and the instrument reads the difference. Nothing gets wet, a failing watch is not made any worse, and the test takes a few minutes. This is the test to ask for by name.
A wet test lowers the watch into water, pressurizes the chamber, then releases the pressure and watches for a stream of bubbles escaping the case. It is cheap, visual and unambiguous about where a leak is. It also finds the leak by allowing water to reach the case, which is exactly what you were trying to avoid. Sensible practice is a dry test first, and a wet test only to locate a leak the dry test already proved.
A good shop will also do a condensation check: warm the watch, put a drop of cool water on the crystal, and look for misting on the inside of the glass. That is the same principle ISO 22810 uses, and it catches moisture already inside the case.
What it costs
A pressure test is one of the cheapest things a watchmaker does. Expect roughly $25 to $60 at a typical US shop for a dry test, quoted before sales tax, with big-city benches at the top of that band and other countries pricing to their own labor rates. It is often free if it is bundled with a battery change or another job you are already paying for. Some authorized service centers include a water resistance check as part of any warranty work.
If the watch fails, the fix is usually new gaskets and a reseal, followed by a retest. That is still a modest bench charge compared with what water damage costs: a flooded movement means disassembly, rust removal, replacement parts and a full service, which commonly runs into the hundreds of dollars. The economics of an annual test are not close.
When testing is not enough
A pass tells you the case held pressure on the bench that day. It does not promise the seal will still be good in eight months, and it does not cover the things a rating never covered: hot water, steam, soap, an unscrewed crown or a hard impact. Retest after any knock hard enough to worry you, and after any case opening at all.
It also does not substitute for judgment about the rating itself. A 30 m watch that passes its test is still a 30 m watch, and our water resistance checker will tell you what that covers. If the crystal is chipped, if the crown feels gritty, or if you have already seen fog under the crystal, skip the test and get the case opened, because you already know the answer.
For the full picture of what gets replaced and when, see our servicing and care guide and the water resistance guide.
Common follow-up questions
Will a jeweler pressure test a watch they did not sell?
Most independent watchmakers will, and many will do it while you wait. Mall jewelry counters often cannot, because the machine is a bench instrument rather than a counter tool. Call ahead and ask specifically whether they run a dry test and whether they can retest after fitting new gaskets.
Does a pressure test damage the watch?
A dry test does not. It applies air pressure to a sealed chamber and measures how much the case deforms, so nothing wet ever touches the watch and a failing watch is no worse off. A wet test puts the watch in water, which is why it is normally used only to locate a leak already identified.
What does it cost to fix a watch that fails?
It depends entirely on what failed. New gaskets and a reseal are a modest bench job. A new crystal, a new crown and tube, or a case with corrosion inside is a different order of expense, and a full mechanical service commonly runs into the hundreds of dollars. Our answer on service costs breaks it down.
Is a home water resistance tester worth buying?
For most owners, no. Inexpensive consumer testers exist, but reading case deformation reliably takes a calibrated instrument and someone who runs one regularly. At roughly the price of two or three professional tests, a cheap tester that gives you false confidence is a poor trade.
Sources and further reading
- ISO 22810, Horology: Water-resistant watches. The international standard defining overpressure, immersion, condensation and temperature-change testing for ordinary water-resistant watches, including sample testing.
- ISO 6425, Horology: Divers' watches. The standard requiring that each individual divers' watch be tested rather than a sample of the production run.
- Technical documentation from watch pressure-testing equipment makers such as Witschi and Roxer, describing dry testing by air overpressure and case deformation measurement, and wet testing by immersion and bubble detection.
- Manufacturer owner's manuals and service documentation from brands including Rolex, Omega and Seiko, which recommend periodic water resistance checks and gasket replacement whenever the case is opened.
- Federation of the Swiss Watch Industry FH, published guidance on water resistance marking and the need for periodic verification.
Last reviewed 4 September 2026. Spotted an error? Tell us and we will fix it in public.