The humble mechanical dive watch has seen its popularity surge over the last few years, and with good reason. As the perfect all-rounder, you can wear your luxury mechanical dive watch to the office with a suit, and then simply roll up your sleeves for a night out at your favourite restaurant or bar. And because they are generally more robust, you can wear your dive watch for all your weekend activities too, including, of course, diving (or just plain old swimming, as you prefer.)

Not all dive watches are created equal, however, which is why we’ve put together this quick Winsor Bishop guide on what to look for when choosing the perfect mechanical dive watch.

A brief history lesson

These days recreational diving is a popular hobby for millions of people around the world. Jet off to somewhere warm and in between lazing by the pool and ordering room service, you strap on some flippers, grab a mask and snorkel and go frolic with the local sea life. It may surprise you to learn, however, that recreational diving is still a relatively recent phenomenon. In fact, the idea didn’t really gain momentum until the 1950’s, when diving started to become a popular pastime instead of just a military activity.

Back then, dive watches were designed to meet the perceived demands of divers and were modified based on their immediate feedback. Nowadays, there are minimum requirements for mechanical dive watches, which are set out in the ISO 6425 standard that was introduced in 1996. These standards are based on everything we’ve learned since the original dive watches were introduced in the 1950’s. They also provide excellent guidance on what you should be looking for when choosing the perfect dive watch, which we have distilled into 4 key criteria for you:

1. Water Resistance To A Minimum Of 100m

It goes without saying that a dive watch needs to be water resistant, after all if it can’t be worn underwater without getting damaged, what’s the point? According to ISO 6425, a watch must be water resistant to at least 100m to satisfy the standard. The 41mm Tag Heuer Aquaracer in steel with black dial more than satisfies this requirement with a water resistance rating of 300m (or 1,000 feet). Certainly enough to accompany you on a few laps in the pool or some serious underwater exploration.

2. Unidirectional Rotating Bezel

First of all, what is it? Well, as its name suggest, a unidirectional rotating bezel is a bezel that can only be rotated in one direction. When used in conjunction with the minute hand, the bezel allows the diver to track elapsed time, for example when they are ascending from a deep dive and need to do so in timed increments to avoid decompression sickness. According to ISO 6425, this rotating bezel must have a minute scale going up to 60 minutes, with the markings indicating every 5-minute interval clearly indicated. A perfect example of this can be found in the 43.5 mm stainless steel OMEGA Planet Ocean Master watch with blue dial. Crafted from steel with a blue ceramic insert, this unidirectional rotating bezel also boasts OMEGA’s Liquidmetal® diving scale.

3. Running Seconds Indicator

Although you probably don’t need to know the time to the second when your diving underwater, you do want to know that your mechanical watch is still running. The easiest way to tell this is via the running small seconds indicator, which completes a full rotation every sixty seconds. Not surprisingly then, the requirement for a running indicator is also included in ISO 6425. That’s why the central seconds hand on the Tudor Heritage Black Bay Dark features a prominent, diamond-shaped tip filled with luminous material, so you can easily spot it at a glance.

4. A Luminous Dial

As we’re sure you’ll agree, a dive watch is only useful underwater if you can actually read its indications. Not wishing to leave anything to chance, however, ISO 6425 has given very specific guidance about this, stating that the following items of the watch shall be legible at a distance of 25 cm (9.8 in) in the dark:

–           time (the minute hand shall be clearly distinguishable from the hour hand);

–           set time of the time-preselecting device (i.e. the unidirectional rotating bezel);

–           indication that the watch is running (i.e. the small seconds hand.)

The Tudor Pelagos, considered one of the most complete mechanical dive watches on the market, satisfies all criteria for a luminous dial and then some. Not only are its trademark snowflake hands coated in the luminous material, but so are all the hour indices on the dial as well as all the indications on the unidirectional rotating bezel.

We hope you have found our Winsor Bishop guide to choosing a mechanical dive watch useful. If you would like to learn more about mechanical dive watches and view the models we have available, please visit us at either of our Norwich or Cambridge boutiques.