Long before watches were capable of exploring the deepest recesses of the ocean, it was enough of a struggle to develop a watch capable of withstanding the rigours of being outside of a coat pocket. Pocket watches were pampered beasts living in a padded, suspended environment; early wristwatches simply weren’t robust enough to cope with life outside. One early solution – the first patent was filed by Gruen in 1919 – was the hermetic case. This two-part, screw-down outer case sealed a watch inside and was adopted by Rolex, Zenith and Eberhard.

The solution was impractical as the watch could not be adjusted or wound while inside and the frequent unscrewing severely limited the life of the case. But it was effective enough that it lasted beyond 1926, the year in which Rolex revealed its Oyster case which presented a far more elegant, technically accomplished solution to water resistance.

Rolex
Rolex

The Rolex Oyster case saw bezel, crown and caseback all screw down into a solid case middle. In the 1930s Omega developed the first diver’s watch intended for commercial use, the Omega Marine, which used a sliding outer case. The watch was certified as water-resistant to a depth of 135m in 1937.

Omega
Omega

Legibility

Air is not the only thing that divers must forgo at depth – light too begins to be absorbed the deeper one goes, with different colours disappearing at different depths; red first, blue last. Legibility remains key for any diving instrument and as diving advancements in the early 20th century led to an increase in both military and commercial diving, one of the first companies to work on developing better underwater legibility was Officine Panerai.

Panerai
Panerai

In 1916 the Florentine manufacturer of nautical instruments for the Royal Italian Navy developed a luminous radium-based powder and paste called Radiomir, which excelled underwater. It wasn’t until 20 years later, on the eve of the Second World War, that Panerai produced the very first prototype dive watches that were recognisable as Radiomir models for the frogmen commandos of the First Submarine Group Command.

They went into production two years later in 1938 with an improved specification – aided by case and movement support from Rolex – that included, for the first time, the sandwich construction dial.

Enter the tool watch

In the post-war boom years, diving had become something of a cultural phenomenon thanks to the 1942 invention of the aqualung as well as the well-publicised underwater exploration of its co-creator, Jacques Cousteau, and Omega released its first Seamaster in 1948. Enhanced legibility and water resistance had become staples of a diving watch, but we were yet to see any of the bespoke functions that came to mark them out as practical tools.

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QP

That changed in 1952, when the leader of a newly formed unit of French combat divers designed a watch that would actually assist his men while diving. Capt Bob Maloubier, above, took his designs to French watch giant LIP, which could not be convinced of the project’s viability. Blancpain eventually agreed to manufacture the watch with Blancpain company director and keen diver, Jean-Jacques Fiechter, refining the original design even further.

Blancpain
Blancpain

Released in 1953, the Fifty Fathoms set the standard for dive watches with hour markers of different shapes for more intuitive use, a unidirectional rotating bezel with 15-minute scale and an automatic movement. These fundamental principles have set the standard ever since and the watch was quickly adopted by combat diving units around the world including the US Navy SEALs.

The Submariner

Blancpain may have beaten them to market, but Rolex’s own work on increasing water resistance was even more ambitious, driven by company director Rene-Paul Jeanerett who was also a keen diver and friend of Cousteau’s. In September 1953, the adventurer Auguste Piccard took a submarine to a depth of more than 3,100m with a Rolex strapped to the hull to prove what Rolexes were capable of. At Basel the following year Rolex released the Submariner, a watch that, for generations since, has defined not only what a diving watch looked like but what sports watches in general looked like.

Rolex
Rolex

Rolex would better its own astonishing achievement in 1960 when Auguste’s son, Jacques, would reach the deepest point of the ocean, the Mariana Trench, in the Bathyscaphe Trieste with Lt Don Walsh. Another experimental Rolex attached to the hull survived this journey, more than 10 times the depth of the first dive. Rolex became the undisputed masters of the deep.

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Jean-Daniel Meyer

Refinement

With two such dominant forces in the field of diving watches other brands were quick to realise the potential of producing watches that were viewed as indispensible instruments by commercial and military divers. After all, at this point in history diving watches still providing potentially life-saving functionality. Japanese watch giant Seiko produced its first diver’s watch in 1965, keen to be seen as capable of producing a watch as technically capable as the Swiss. The 62MAS was water resistant to 150m, but exhibited a number of weak points in its design, a point made in a letter to Seiko by a Japanese commercial diver disappointed by the watch’s habit of popping crystals because of helium incursion and poor shock resistance at depth.

Seiko
Seiko

While Seiko evolved its fledgling diver line with three further models, the company clearly took the letter to heart and set a team of engineers, led by Ikuo Tokunaga, to creating the ultimate diving watch. The 6159-022 – nicknamed the Tuna Can – was released in 1975 and flew in the face of traditional thinking. It was water resistant to 600m and ignored the helium release valves entirely, preferring to use a double case so solid that helium could not enter.

Seiko
Seiko

Looking to the future

As the end of the 20th century approached, you might be forgiven for thinking that the development of diving watches, which had already been outmoded by digital equivalents in the 1980s, had ground to a halt. Not so. In 1999, IWC completely reinvigorated the field with the Deep One, a watch that mechanically gauges depth and, more importantly for divers, maximum depth, by means of a Bourdon Tube, which allows water inside and straightens from a curve as pressure increases.

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Krause & Johansen

The complication was the work of Richard Habring, then an IWC watchmaker, who has since won three consecutive GPHG awards for his own Habring2 watches. Oris later reprised the idea of a mechanical depth gauge on the Aquis Depth Gauge (and at a considerably lower price). Other brands continuing to find space to innovate in the diving watch market include Ressence, whose Type 5 Diver boasts legibility from any angle thanks to its liquid-filled display.

Ressence
Ressence