A Guide to Waterproof Watches - Water Resistant or Waterproof?

Having a waterproof watch is really convenient for both everyday life and great adventures. It gives you the freedom to not have to think about protecting it the second it starts to rain, and can be a way for you to time your next swimming lap.

It can often be confusing when watches are labelled as ‘waterproof’ or ‘water resistant’ though. What’s the difference? And how do we know what our watch is really capable of? We’ll go through the details of waterproof watches so you know what you can and can’t do.

The terms waterproof and water resistant get tossed around and used interchangeably, but what do they really mean? Are they the same thing?

They’re actually two different things:

• A water resistant watch can withstand a certain degree of contact with water
• A waterproof watch is designed to be impenetrable by water

There are varying degrees of ‘water resistance’, commonly measured in ‘meters’ and displayed on the watch face. These range from 30m all the way to depths of 1,000m, but your standard watches will sit within 30m and 300m. It’s a common misconception that this number allows you to go deep sea diving at these depths. It’s easy to make the assumption that the number of metres is a direct description of how far down you can go, but that doesn’t account for the change in pressure.

A 30m water resistance rating only covers accidental splashes from the rain or washing up. A 50m watch is suitable for gentle swimming, but it's not until you reach ratings of 100m that a water resistance watch becomes suitable for real watersports.

The reason most watches are deemed water resistant rather than waterproof is because there are so many factors to consider. Changes in temperature and pressure can cause a lot of issues, leading to leaks.

Waterproof watches do exist and allow for full submersion. However, it’s a good idea to repair the seals every few years as they can weaken over time thanks to temperature fluctuation.

There are specialist watches that are designed to withstand significant depths and pressures. These are marked as 1,000m to allow for actual deep sea diving. It’s really only these watches that are guaranteed to be waterproof.

If you’re more concerned with an everyday level of waterproofing that allows you to go in a pool (rather than exploring lost shipwrecks!), then a rating of 100m would be enough to go swimming. Just make sure you avoid diving or showering with your watch - the immediate change in pressure and temperature will break the seal and force water into the mechanism.

Waterproof watches are made in a similar way to ordinary watches, but with a few extra reinforcements. Some of the main differences include:

Gaskets

These are also known as ‘0-rings’ and form a watertight seal where all the components join together. Typically made out of rubber, nylon or Teflon, they make a ring around the edge of the case and around each pusher (if it’s a chronograph watch).

Sealant

Waterproof watches will have additional sealant in the case. A ring of hardening liquid is added to help keep water out of the watch.

The case

A waterproof watch has to be able to withstand pressure. The case of a waterproof watch will be made out of stainless steel or titanium - or solid gold if it’s thick enough.

The case will also be attached differently; it will use a screw-in case rather than push-in, so it will have a much tighter seal.

Waterproof watches then go through a vigorous testing process. This can be done by two types of test: a dry test or a wet test.

• Dry test: As the name suggests, this test is carried out when the watch is dry to see if any air leaks in when it’s put under pressure.
• Wet test: This involves a full submersion of the watch in water before adding pressure.

It’s important to remember that watches don’t stay waterproof forever. Maintenance is inevitable no matter how well you care for your watch, and parts will need to be replaced over time, particularly the gaskets. However, increasing the longevity of your watch is a simple matter of science:

• Avoid drastic changes in temperature (in places such as the shower or sauna). The heat causes the metal to expand at different rates to the gaskets as they are made out of rubber. This difference can create gaps for water to seep into the watch itself, ultimately damaging it.
• Avoid submerging your watch in salt water. If you can’t help it, make sure you rinse it off immediately where possible to avoid corrosion.
• Be careful around certain chemicals. This includes chlorinated water and also some perfumes as they can damage the gaskets (which are fundamental to the water resistance).
• Don’t press any of the pushers while the watch is submerged.

You’ll most likely come across ‘water resistant’ watches more frequently than waterproof ones, so you can use this guide to determine what depth you would need depending on how you want to use your watch. There’s a level to suit everyone and it’s possible to have a fully waterproof watch - it just needs to be maintained too.

Within the following brands or collections, you're likely to find a few water resistant watches:

• Marathon watches and U-Boat watches.

You may want to explore from:

• Casio watches
• G-Shock watches
• Garmin watches