# How Bars Are Used To Measure Water Resistance In Watches [3/5/10/20 Bar, Etc.]

Before taking a shower or swimming with your watch on, you need to know how water-resistant your watch is. Water resistance ratings are measured in bars, and can often be found on the watch’s dial, case back, or in its specifications. But, what exactly are the bars, and how are they measured?

The more bars your watch has, the more water resistant it is. 1 bar is equivalent to 10 meters (about 33.46 feet) of water resistance

A watch with 3 bars has a 30 meter/3 ATM/100 feet water resistance rating, suitable for minor moisture from splashes, such as washing your hands or getting caught in the rain. A watch with 3 bars should not be used for swimming, diving, or showering.

A watch with 5 bars has a 50 meter/5 atm/165 feet water resistance rating suitable for swimming in shallow water but should not be used showering, snorkeling, diving, or other water sports.

A watch with 10 bars has a 100 meter/10 atm/330 feet water resistance rating suitable for swimming or snorkeling. Although watches with 100 meters of water resistance are sometimes called dive watches, it is best to avoid diving with a watch with less than 20 bars.

A watch with 20 bars has a 200 meter/20 atm/660 feet water resistance rating suitable for showering, swimming, snorkeling, and even diving. Watches with 20 bars is the best compromise between

Of course, a watch with more than 20 bars of water resistance can be worn on a dive to even deeper depths and is suitable for all the above activities.

In this post, we tell you precisely how bars are measured and how to find out how much water resistance your watch has. At the end of the article, we’ll also look at some of the most water-resistant watches in the world!

## What Are Bars?

Simply put, a bar is a metric unit for measuring water pressure. 1 bar is equivalent to 14.7 pounds (or 10 meters) per square inch (PSI).

Watches with more bars of water resistance can withstand being submerged in higher water pressure levels and be used for more water activities.

I.E. watch A has 3 bars of water resistance, and watch B has 10 bars of water resistance. Watch A shouldn’t be used while swimming, or it would significantly risk water damage. Watch B can be worn while swimming as long as it is well-maintained and the rubber gaskets that keep water out are in good condition.

This unit is not just used in watchmaking but also scuba diving, engineering, and even the automotive industry.

### How Are Bars Measured?

1 bar is approximately equal to:

• 1 ATM (atmosphere)
• 33 feet
• 10 meters

## What Do the Different Bars on a Watch Mean?

In this section, we’ll give examples of the different levels of water resistance and the water activities it can be safely exposed to, such as:

• Washing hands
• Swimming
• Snorkeling
• Diving
• Water sports (jet skiing, etc)

Note: The bars listed on a watch tell you its water resistance at the time the watch was manufactured. Years later, the watch’s water resistance may degrade as the watch ages and parts fail. We’ll explain later in this article how to make sure your watch is well-maintained and how to check its water resistance.

### What About Hot Tubs and Showers?

Although a watch might have a water resistance rating suitable for something as shallow as a hot tub, or a quick shower, you should generally avoid both with your watch.

It’s not the water that’s the issue, but the steam and heat that can cause the gaskets in the watch to contract, removing the seal that otherwise keeps water out of the watch.

## Watches Are Water Resistant, NOT Waterproof

You now know which activities are safe to do while wearing a watch based on its bars. But we need to take this moment to stress an important caveat: there is no waterproof watch.

You probably know that any product sold as “waterproof” will only withstand water for so much time or at so much pressure before springing a leak.

Due to legalities, watches are not even allowed to be marketed as “waterproof.” During the ‘60s and ‘70s, consumer protection groups took legal action against watch manufacturers. Reportedly, the failure of a watch underwater may even have contributed to a diver’s death. Since then, the Federal Trade Commission has flat-out banned the “waterproof” label for watches.

In short, you can generally trust a quality water-resistant watch to perform as expected for the bars listed, but if you dive with it, you are doing so at your own risk. There is always a chance that a watch’s water resistance may fail.

## How To Tell How Water-Resistant Your Watch Is

If you already own a watch and are unsure what level of water resistance it features, there are a few different methods you can find out.

### Get it Pressure Tested by a Watchmaker

The most accurate option is to take your watch to a watchmaker. They can safely run a pressure test with specialized equipment to determine how much water pressure the watch can withstand.

Most watchmakers will check the water resistance of your watch for free or for a few dollars.

Not only can they give you feedback on the current water resistance of your watch, but they can also alert you to any specific issues. If there are opportunities to improve your watch’s water resistance, they can give you a personalized quote on a repair.

### Check the Dial

Sometimes, a watch’s water resistance is written right on the dial, expressed in bars, ATM, feet, or above. This is typical in dive watches, where their water resistance is generally more critical and expected to be higher.

Some watches, however, have “water-resist” or “water-resistant” on the dial, which doesn’t tell you how water-resistant it is. It might be water resistant up to just 1 bar, which isn’t water resistant at all!

That’s why it’s important to understand bars as a measure of a water resistance rating and just how water resistant your watch is.

### Check the Caseback

Another place you can sometimes find the water resistance of a watch is on the case back.

Speaking of the case back, the case’s materials and design can also tell you something about your watch’s water resistance.

You can also check whether the back pushes in or screws in. If it screws in, it will generally be more water-resistant, although this is not always the case.

### Screw-Down Crown

Just as you want a case back that screws in, a watch with a screw-down crown will likely have better water resistance. Screw-down crowns are typically found in watches with at least 20 bars or 200 meters of water resistance.

Note: If a watch has a screw-down crown, its water resistance will only apply if it is screwed down. Don’t forget to screw down the crown before diving in the pool or the ocean!

If it is snugly screwed down, it will seal off the space between the crown and the watch, preventing water from seeping through.

### Check the Specifications

One more thing you can do is look up the manufacturer’s specs for the watch. The specs will typically list its “water resistance” in bars, meters, feet, ATM, or all of the above.

## Watches with the Most Water Resistance

### OMEGA Seamaster Planet Ocean Ultra Deep Professional (1,500 bars – 15,000 meters)

If you thought your 20 bar Seiko was impressive, wait until you behold the OMEGA Seamaster Planet Ocean Ultra Deep Professional with 1,500 bars, or 15,000 meters, of water resistance.

Omega has a reputation for engineering cutting-edge watches for epic missions, such as those by NASA. This watch was created for a record-setting dive by Victor Vescovo during a Five Deeps Expedition where the explorer set a new world record for the deepest dive, descending 10,935 meters.

To ensure the watch would perform, OMEGA went above and beyond. They tested it to operate at depths of up to 15,000 meters

The watch’s design draws inspiration from the viewports on submersibles. This design choice is more than merely an aesthetic one. The viewports are designed to withstand incredible forces of water pressure and are the perfect design for such a watch.

### The Rolex Sea-Dweller (120 bars/1,220 meters) and the Rolex Deepsea (390 bars – 3,900 meters)

The Rolex Deepsea Sea-Dweller is one of the most water-resistant watches in the world. It has a water resistance of up to 390 bars, or 3,900 meters, and has been around since 2008.

To reach such insane levels of water resistance, Rolex introduced a special alloy case back and a sophisticated ring lock system to secure the crystal into place. It also has a special helium escape valve that prevents damage to the watch in decompression chambers. In 2014, the D-Blue Rolex Deepsea variant paid homage to James Cameron’s record-breaking 2012 solo dive to the base of the Mariana Trench.

The first Rolex Sea-Dweller had a still impressive rating of 120 bars. The brand developed the Sea-Dweller ref. 1665 in 1967, and released it to the public in 1971. Rolex is still manufacturing new watches in the Sea-Dweller line today.

If you want a vintage model 1665, you may need to save a lot of money. The watch generally sells for between \$15,000-\$50,000.

### UTS 4000M Dive Watch (400 bars/4,000 meters)

While Rolex is a name most people know, you may not be as familiar with UTS. This German watch company is the creator of the 4000M Dive Watch, an impressive timepiece that we would be remiss to overlook.

This handcrafted watch features a German-made 45mm stainless steel case and a 6mm sapphire crystal. UTS fabricated the case from a single piece of steel to minimize potential weak points in the design.

A proprietary ceramic ball-bearing system locks the rotating bezel. Interestingly, it doesn’t even need a helium escape valve, unlike other watches that are taken to massive depths.

## Summary

It is essential to know how water-resistant a watch is before you expose it to water. We hope this article helped you find out just how water-resistant your watch is and how deep it can now be submerged.

Here is what we learned:

• Watches can be water-resistant, but no watch is “waterproof.”
• Water resistance for watches is expressed in bars or meters.
• The number of bars or meters can help you determine if it is safe to wear your watch when snorkeling, diving, or performing other water-based activities.
• A sturdy, thick case made of solid metal, a screw-in case back, and a screw-down crown all contribute to water resistance. To determine if your watch is water-resistant, check for these features or see if the manufacturer has listed the bars.
• Water resistance degrades with time and wear. Taking your watch to a watchmaker to check the water resistance is, therefore, the best way to get an accurate idea of what your watch can handle.

Now you can enjoy your watch doing all the water activities you love to do, so long as it has enough bars for the job!