Diving has a been a sport and science since the early 20th century. And before the age of diving computers and advanced technical equipment, there was the dive watch. Dive watches serve the primary purpose of recording the time a diver spends underwater, but they’ve found a place on the wrists of desk divers and sports enthusiasts alike. It’s gotten to the point where any water resistant watch is called a dive watch, when that’s not always the case. Let’s take you in-depth about what separates real dive watches from the pretenders.

Dive Watches: Blancpain Fifty Fathoms

So, What Makes a Dive Watch a Dive Watch?

All dive watches are timepieces, but not all timepieces are dive watches. Here’s how.

ISO Standards

Regulations laid out by the International Organization for Standardization (ISO) determine what watches can claim to be true dive watches. Otherwise, you’ll find marketing materials that simply say ‘water resistant’ or something similar. The ISO 6425 Diver’s watch standards list the requirements and features found in conforming dive watches, including testing parameters and design compliance.


ISO Specified Dive Watches

According to ISO 6425 standards, mechanical dive watches must possess the following attributes:

1. A rotating bezel that specifically allows divers to track the total time elapsed under water from the beginning of their dive

2. Luminescent features on the dial and hands that allow for easy readability underwater

3. A screw-down crown that keeps water from entering the watch

4. A case made of water-resistant materials that protect the watch from corrosion and rusting

6. A movement that has both shock resistance and magnetic resistance

7. A minimum water resistance  of 100 meters (330 ft)


ISO Testing

Testing standards dictate that a watch undergoes several pressure tests to ensure that the case, crown, and crystal are properly water-resistant and can withstand plenty of pressure. A watch that conforms to ISO Standards is marked with the word DIVER’S to distinguish it from other water-resistant watches.

Dive Watches: Cartier Calibre De Diver

The Cartier Calibre de Diver has the ISO-Specified wording on the caseback

An important thing to note: ISO doesn’t actually certify or test watches themselves. Which means that you’re going off the watch company’s word when it comes to an ISO-standard watch.


So, ISO: Yes or No?

Dive watches were around long before ISO introduced the 6425 Diver’s watch standards in 1996 (Read: Dive Watch History). And watch brands spent decades perfecting and testing the dive watch to extremes. So it’s very likely (even guaranteed) that you have plenty of dive-worthy watches out there that perform just fine without the ISO stamp of approval.

Dive Watches: Rolex DEEPSEA Sea-Dweller

The Rolex DEEPSEA Sea-Dweller exceeds ISO Standards

What you have to understand that ISO standards are a minimum requirement, and many companies often develop watches that exceed them (Rolex’s DEEPSEA Sea-Dweller is a good example). So you can find a serviceable dive watch that doesn’t have the DIVER’S on the case or dial. It all depends on what you’re really looking for.


What Kind of Dive Watch is Right for You?

Not all dive watches are made equal. Are you a diving enthusiast looking for a reliable tool, or do you like the look but don’t need all the fixings?

There are a few factors to take into consideration, including your diving experience and the type of dives you partake in. If you’re an experienced diver, a watch with a higher water resistance is important. The best tools for those challenging deep dives are watches with a water resistance rating of 200m or greater. And, if you’re saturation diving, a watch with an even deeper water resistance of at least 300m is imperative. (Read: The Dive Watch Buying Guide)

Dive Watches: Tudor Black Bay

The Tudor Black Bay has a depth rating of 200m

On the other hand, if you’re sticking to shallow waters, you really only need a watch that meets the minimum ISO 6245 standard of 100m. Or, you can always find a good water resistant watch that will do the trick.



Editor’s Note: This article was originally published on August 6, 2015. We have updated it to include more information.

Image Credits: Header; OMEGA Forums. 1-4; Crown & Caliber.

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Latest comments
  • So panerai has no screw do crown. Theref its not a proper divers watch???

    • Most Panerai watches are depth-rated to at least 100m, which means they should be fine to use in diving. But according to ISO standards, no, they aren’t “diver’s watches”.