You’re at the bottom of the ocean on an all-day dive … do you really need to know what the date is?

The obvious answer might be “no,” but the Rolex Submariner wasn’t meant just for diving. It was meant to split the gap between dress watches and sports watches and tool watches, providing the perfect universal wristwatch for mornings in the boardroom, afternoons on the yacht, and long weekends plumbing the depths of the sea.

Thus, the date-and-cyclops combination makes great sense for everyday wear. In addition to living up to the classic Rolex mythos of being recognizable from 20 feet away, it serves a practical purpose in the office and on-the-go.

But the date function isn’t the only functional feature of everyone’s favorite Rolex watch …

The Bump-Proof Unidirectional Bezel

One of the most characteristic features of the modern dive watch is the classic unidirectional bezel—born with the Blancpain Fifty Fathoms back in the 1950’s, it’s a definitive feature on the world’s most popular tool watches.

In the early days of deep-sea diving, the watch was an essential piece of equipment for measuring time underwater, coordinating with fellow divers, and knowing how much air you had left in the tanks.

But why unidirectional? And why only counter-clockwise? The answer is cleverer than most watch enthusiasts realize …

By only rotating in one direction, the bezel is more resistant to bumps and knocks that could accidentally reconfigure it. And by only rotating in the counter clockwise direction, it ensures the diver’s safety—only ever shortening the dive time in the case of an accidental adjustment. It’s an invaluable feature when it comes to deep saturation dives, where every second matters.

With shallow cuts on its edge and a tough action, the unidirectional bezel becomes even more reliable. Rolex Submariner bezels are marked in the classic 60-minute gradient, with a luminescent marker at the very top of the dial.

Historically, most Submariner bezels have been made steel—with a paint finish that develops a desirable, fading patina over time. In recent years, they’ve been replaced with ceramic inserts that don’t patina, but catch and reflect the light like no other.

Another often-overlooked feature of the Rolex Submariner comes with the crown guards. Most recent references incorporate practical guards into the case design, ramping up on either side of the crown to protect it from unexpected jarring that might occur during a deep-sea dive or a dinner on the town. These crown guards have become one of the clearest defining features separating modern design from classic vintage Rolex watches.

Superior Water Resistance

One of Rolex’s earliest advertising campaigns involved a simple fishbowl—with an Oyster case sports watch submerged underwater in the window of a jewelry store.

The message was obvious, and striking, at the time. Unlike most early wristwatches (which were easily damaged by water), Rolex’s oyster case watches provided a practical defense against handwashing or doing the dishes that made them that much more convenient and practical for everyday use.

As dive watches became more popular, the importance of water resistance grew. The Submariner first began as an evolution on that classic oyster case, incorporating the timing bezel and an easy-to-read white-on-black face. With the first Submariner, Rolex unveiled a watch with 100 meters of water resistance.

Over future references, the number rose to 200 meters. Another basic feature, now known as the “Mercedes” or “Cathedral” hour hand was included, improving visibility and legibility even in the depths of the ocean. In 1979, The 16800 reference incorporated a sapphire crystal and boosted the water resistance to 300 meters, where it’s rested since.

As a side note, have your Rolex submariner serviced at regular intervals to ensure the watch remains water resistant and always check the screw down the crown before any deep sea adventures.

Cobbling Together a Masterpiece

Today’s Submariner is a subtle masterpiece of design and practical function—so subtle, in fact, that it’s hard to imagine it coming together over generations of evolution and design …

From the cathedral-style hands to the 300 meter water resistance, to the bulkier “maxi-lug” case, crown guards, sapphire crystal and ceramic bezel, today’s Rolex Submariner is both reserved and audacious. Both conservative and groundbreaking.

But with such a history and such a rich heritage, it’s not so surprising that today’s modern sports watch should be so straightforward—no chronograph, no GMT hand or stopwatch—just a unidirectional rotating bezel, simple crown guards and a date window with a cyclops magnifier (which in itself is optional).

Today’s Rolex Submariner is a masterpiece of simplicity and function … an icon, and a tool watch for the ages.