So dangerous is the quest to explore the depths that more is known about the surface of Mars than of the blue liquid that covers two-thirds of our planet’ surface.
Not that danger has ever stopped mankind from exploring anything; records show that people have been deep-sea diving since ancient Roman times, often for combat, either by holding their breath or using long reeds as snorkels. The Greek philosopher Aristotle even described the first known diving bell as ‘a container not filled with water but air, which consistently assists the submerged man.’
The diving bell continued its development throughout the centuries, always following the same basic principle of trapping air inside an upturned container. By 1619, Sir Edmund Halley had adapted the concept further to include a tube from the diving bell that fed a sealed helmet, allowing the diver wearing it to freely walk the ocean bed without having to return for a fresh breath of air. The air supply in the main bell could even be replenished from barrels that were lowered down from the surface.
A century later and the diving bell had been replaced by longer hoses that directly fed a sealed diving suit, with bellows extracting the old air and pumping in new. By far the biggest leap in diving technology came in 1808 when French Naval mechanic Sieur Touboulic patented a self-contained oxygen tank that allowed the diver to carry his own supply of air with him, and a working design appeared twelve years later. Deeper diving began to expose the problem of decompression sickness, or ‘the bends’, a condition brought on by dissolved gases entering the body and becoming trapped inside during rapid decompression.
Up to this point, the diving suit had been large, heavy and cumbersome, but the early nineteenth century paved the way for more compact diving apparatus. Air could now be compressed into compact cylinders, with carbon dioxide scrubbing chemicals used to allow air to be rebreathed. With World War One recently over and World War Two just around the corner, the military application of diving technology accelerated the progression of development, not only for the diving apparatus itself, but also for the accessories that were necessary to dive safely.
One such accessory was the diving watch, which offered the crucial measure of time. This was important for two reasons: to keep track of air usage and to time decompression stops when resurfacing. Although some watches with the capability of being submerged in shallow water without leaking already existed, it wasn’t until 1932 that Omega released the first properly waterproof diving watch, the Marine. Rated to a depth of 135 metres, the Marine incorporated a sliding outer case that sealed the inner case from water.
Panerai’s commission from the Italian Navy prompted the next investment in watertight watches. Manufacturing technology had become accurate enough to create a tight seal without the need of a secondary case, and so the radium-painted Radiomir came into service with military divers.
In 1942, Émile Gagnan met Jacques-Yves Cousteau to combine his recently invented miniature regulator with a portable gas cylinder. This revolutionary device significantly reduced the size of diving equipment; previously, a sealed helmet with a constant-feed air supply was used – which was of course bulky and awkward – but now only a mouthpiece was needed, the air feed regulated by the diver’s inhalation. Cousteau’s freely-available CG45 ‘Aqualung’ turned diving from a dangerous necessity into an enjoyable hobby almost overnight.
Even deeper diving called for the invention of the next diving watch feature, the rotating bezel. Beating the Rolex Submariner to the post by just a few months, Blancpain’s 1953 Fifty Fathoms incorporated a rotating bezel with minute markers that could be used as a countdown timer for air and decompression. The simple, yet incredibly intuitive idea found its way onto Jacques Cousteau’s wrist for the 1956 film ‘Le Monde du Silence’.
As commercial diving became more lucrative, the depths dived and the time spent underwater increased. Saturation diving so named because the body becomes saturated with inert gases exposed divers to increased pressures for longer periods of time, which in turn required longer periods of slow decompression to prevent decompression sickness. Military research and commercial interest required a watch that could withstand pressures far higher than the current diving watches were capable of, and so the development race began to create the saturation diver’s watch of choice
The problems encountered by watch manufacturers were twofold – the first being the seals of the watch leaking under high pressure, and the second being the structural integrity of the components during decompression. As divers desaturated after a long dive, they found that the gases that had entered the watch under pressure could not find their way out again, and the result popped the crystals off.
Alongside commercial diving company COMEX, Rolex developed a special gas escape valve for the Submariner 5513 that allowed the saturated gases to be released during decompression. At the same time, a new, sturdier design known as the as the ‘Sea-Dweller’ was being tested at the US Navy SEALAB II project, which then also inherited the gas escape valve trialled by COMEX. The finished Rolex Sea-Dweller was launched in 1967 and was capable of reaching depths of up to 610 metres.
Meanwhile, Omega investigated a solution that employed brute force over Rolex precision with the Seamaster Plongeur Professionnel or ‘PloProf’, a vast slab of watch with a six-hundred metre water resistance. Unfortunately the Omega PloProf was released too late, three years after the introduction of the Sea-Dweller, by which point the diving companies insisted on their watches having a gas escape valve.
As the eighties came and went, diving watches became diving computers, and so the humble mechanical watch stepped down from its commercial top spot. That isn’t to say that the diving watch is now defunct – far from it. In fact the diving watch is more popular now than it ever has been before.
[Note: This is an updated post of a Guest Article published earlier on our website by Gary Robery from Watchfinder.co.uk]