A Guide to Water Resistance for Australian Watches
Water resistance is one of the most misunderstood watch specifications.
A case back might say 30 metres, 50 metres or 100 metres. Another watch may be marked 3 BAR, 5 BAR or 10 BAR. It is tempting to read those numbers as a simple depth limit, but that is not the best way to use them.
The more useful question is: What kind of water exposure was this watch designed to handle?
This guide explains the common ratings, what they mean in everyday use, why water resistance changes over time, and how to care for a watch that may be exposed to water.
What does water-resistant mean on a watch?
A water-resistant watch is designed and tested to resist water entering the case under specified conditions.
The international standard commonly associated with ordinary water-resistant watches is ISO 22810:2010.
It sets requirements and test methods for watches described as water-resistant, as well as rules around the markings manufacturers may use.
Two watches with the same rating should not automatically be treated in exactly the same way. Construction varies.
Crown design, seals, age and condition all matter, and manufacturers may give different instructions for particular models.
For example, one 5 BAR watch may be intended for swimming while another may have more restrictive care instructions.
The maker's guidance for your exact watch should always take priority over a general chart.
Water-resistant is not the same as waterproof
No watch should be treated as permanently waterproof.
A watch case relies on seals and gaskets around areas such as the case back, crystal and crown.
Some watches also have pushers that need sealing. These parts can age, dry out, shift or become damaged. A hard knock can also affect the integrity of the case.
This is why a watch that was water-resistant when new may not provide the same protection years later unless it has been maintained and tested.
What do ATM, BAR and metres mean?
ATM and BAR are units used to describe pressure. In everyday watch terminology, 1 ATM is approximately equal to 1 bar of pressure.
That means a watch marked 3 ATM and one marked 3 BAR sit in roughly the same pressure category. The same applies to 5 ATM and 5 BAR, or 10 ATM and 10 BAR.
You may also see the rating expressed in metres:
- 3 BAR / 3 ATM / 30 metres
- 5 BAR / 5 ATM / 50 metres
- 10 BAR / 10 ATM / 100 metres
- 20 BAR / 20 ATM / 200 metres
These figures describe pressure resistance under test conditions. They should not be read as instructions to take the watch to that exact depth.
Why a 30-metre watch is not a 30-metre diving watch
A 30-metre rating does not mean you should dive to 30 metres wearing the watch.
In normal use, a watch can face changing pressure, water movement, impacts and temperature changes that differ from controlled test conditions.
For that reason, manufacturers usually translate ratings into practical activities rather than asking owners to rely on the depth number alone.
As a general rule, lower ratings are intended for everyday contact with water. Higher ratings allow progressively more demanding use.
What should you expect from a good wood watch?
For a modern wood watch, 3 BAR is a sensible minimum quality benchmark. At this level, the watch is designed to cope with everyday moisture such as rain, perspiration and occasional splashes.
It should not be treated as a swimming or diving watch unless the manufacturer states otherwise.
Luminius wood watches meet or exceed this 3 BAR benchmark. They are suitable for normal everyday wear when used within their stated water-resistance limits and while the crown, seals and case remain in good condition.
The same basic principle applies when choosing a quality wood watch: check the maker's rating rather than assuming the timber itself determines water resistance.
The case and seals protect the movement, while wooden components still benefit from avoiding prolonged soaking.
A practical guide to common water-resistance ratings
No water-resistance marking
If a watch has no water-resistance marking, keep it dry unless the manufacturer says otherwise.
This is especially important with vintage watches and watches whose service history is unknown.
3 BAR / 3 ATM / 30 metres
This is generally an everyday splash-resistance level. It is suitable for things such as rain, perspiration and small accidental splashes.
It is not a sensible rating for swimming, snorkelling or prolonged immersion unless the manufacturer specifically permits it.
5 BAR / 5 ATM / 50 metres
Many manufacturers describe 5 BAR watches as suitable for swimming and similar surface-water activities.
That does not automatically make them suitable for diving. Check the instructions for the exact watch because crown design, age and condition all matter.
10 BAR / 10 ATM / 100 metres
A 10 BAR watch generally provides a stronger margin for swimming and active water use. Some manufacturers also permit shallow or skin diving at this level when the watch is in good condition.
It is still different from a purpose-built scuba-diving watch.
20 BAR / 20 ATM / 200 metres
A 20 BAR rating is commonly associated with watches designed for more demanding water exposure.
If you intend to scuba dive, use a watch specifically designed and rated for diving rather than relying only on a generic 200-metre marking.
Diver's watches are a separate category
A diver's watch is not simply an ordinary watch with a high number printed on the case back.
Purpose-built diving watches are designed around underwater use and may be tested to a different standard, such as ISO 6425.
They can include additional requirements for water resistance, underwater legibility and measuring elapsed time.
If your activity involves scuba or professional diving, use a watch made for that purpose and follow the manufacturer's instructions.
Can you shower with a water-resistant watch?
It depends on the watch, but showering can be harder on a watch than many people expect.
Warm water can cause materials to expand at different rates. Soap and shampoo can also leave residue around the crown, pushers and case.
Some manufacturers permit showering at particular ratings and others advise against it. If the instructions for your watch do not clearly allow it, removing the watch before showering is the simpler choice.
Hot tubs, spas and saunas deserve extra caution because heat can place additional stress on seals and other components.
Crowns and pushers matter
Unless a watch is specifically designed for underwater operation, do not pull out or turn the crown or press pushers while the watch is wet or submerged.
Moving those controls can compromise the seal at the moment water is present. If the watch has a screw-down crown, make sure it is fully secured before exposure to water.
Salt water and swimming pools
Salt, chlorine and other chemicals can be hard on watches over time.
If the manufacturer allows the watch to be used in the sea or a pool, rinse the case with fresh water afterwards and dry it with a soft cloth.
Only do this if the watch is rated for that level of water exposure.
The strap may have different care requirements from the case, so check those instructions as well.
Maintenance and care
Pressure testing
Water resistance is not permanent. Gaskets age, crowns wear, crystals can be knocked and case backs are opened for battery changes or servicing.
If you regularly swim, work around water or rely on your watch in wet conditions, periodic pressure testing by a qualified watchmaker is sensible.
An annual check is a practical interval for a watch that is regularly exposed to water, and testing is also worth considering after a battery change, case opening or hard knock.
Seiko's official water-resistance guidance notes that ageing gaskets and accidental shock can reduce water resistance and recommends periodic checks.
Signs that water may have entered the case
Condensation or fogging under the crystal, visible moisture inside the case, or damage around the crown or crystal can indicate a problem.
If you see moisture inside a watch, keep it away from further water and arrange an inspection promptly.
Dry the exterior with a soft cloth. Do not use a hair dryer, heater or other strong heat source, as excess heat can damage seals, lubricants and internal components.
Strap care
Water resistance usually describes the watch case, not the strap.
Metal bracelets, rubber straps and some synthetic straps are generally better suited to regular water exposure than leather.
Leather should be allowed to air dry away from heat. Wooden straps and other timber components should be dried gently with a soft cloth and stored in a cool, dry place.
Our guide to cleaning and caring for a wood watch band covers routine band care in more detail.
This distinction is particularly important with wood watches: the movement and case may have a stated water-resistance level, while prolonged soaking can still affect wooden parts.
Older and vintage watches need extra care
A vintage watch may have been sold as water-resistant when new, but that rating should not be assumed decades later.
Cases can corrode, crowns wear and replacement parts may differ from the originals.
Even after servicing, some older cases cannot safely be restored to their original water-resistance level.
Unless a competent watchmaker has tested the watch and confirmed its current condition, keeping an older watch dry is usually the safest approach.
Use the manufacturer's guidance as the final word
The core principle is similar across major watch brands: the number on the case is only part of the picture.
Crown position, seals, age, condition and the instructions for the particular model all matter.
Citizen's official water-resistance guidance explains practical use across 3 BAR, 5 BAR, 10 BAR and 20 BAR ratings.
Swatch's official technical guidance on water resistance also explains water-resistance testing and the role of the crown, pushers, glass, case and gaskets.
If a general guide and the instructions supplied with your watch differ, follow the manufacturer's instructions for that model.
A simple way to read the rating
Use the number as a starting point, then consider the watch's age, condition and intended use.
- 3 BAR: everyday splashes and rain
- 5 BAR: swimming where the manufacturer permits it
- 10 BAR: swimming and more active water use, subject to manufacturer guidance
- 20 BAR: higher water exposure; choose a true diver's watch for scuba diving
If the watch is old, has been opened, has taken a hard knock or has an unknown service history, do not assume the original rating still applies.
Frequently asked questions
Is a 30-metre watch safe for swimming?
Generally, no. A 30-metre or 3 BAR watch is usually intended for everyday splashes rather than swimming. Check the manufacturer's instructions for the exact model.
Is 50 metres enough for swimming?
Often, yes. Many manufacturers rate 5 BAR or 50-metre watches for swimming. The watch should still be in good condition and the crown must be properly closed.
Can I swim with a 100-metre watch?
A 10 BAR or 100-metre watch is generally intended to handle swimming. Some brands also permit shallow or skin diving. Check the manufacturer's guidance before using it for more demanding activities.
Is a 200-metre watch automatically a dive watch?
No. A 200-metre pressure rating and a purpose-built diver's watch are not necessarily the same thing. For scuba diving, use a watch specifically designed for diving.
How often should water resistance be tested?
There is no single interval that suits every watch. For a watch that is regularly exposed to water, an annual pressure test is a sensible precaution.
Testing is also advisable after the case has been opened or the watch has taken a hard knock.
Does replacing a battery affect water resistance?
It can. Opening the case disturbs the sealed system.
The gasket should be checked and correctly seated when the case is closed, and a pressure test is worthwhile if dependable water resistance matters to you.
Does water damage void a watch warranty?
Warranty terms vary by brand and model. Water damage may be excluded when a watch has been used outside its stated limits, the crown has been left open or required maintenance has not been carried out.
Check the warranty wording supplied with your watch rather than assuming all brands apply the same rule.
✦ The bottom line
Water resistance is best understood as a capability with limits, not a permanent promise.
The rating tells you what the watch was designed and tested to withstand. The manufacturer's instructions explain how that rating should be used.
The watch's age and condition determine whether it can still provide that protection today.
For everyday use, match the rating to the activity. If you plan to swim or dive regularly, choose a watch designed for that purpose and keep its water resistance properly maintained.