Watch In Focus – Oris Aquis Depth Gauge

Since the introduction of quartz movements, programmable computers and micro-sensor technology, the mechanical dive watch has become to diving what the horseshoe is to motoring. The day of the tool watch, with its ticking, clicking, pulsing innards, is done, dead, gone. Or is it?

Oris Watches

When the Aqua-Lung – Jacques-Yves Cousteau’s self-contained underwater breathing apparatus – was developed in 1945, divers had no choice but to go mechanical. One wrist was for time, the other for depth, and that was how things were done. Today, a single, cheap watch can do all of that and more, including recording dive logs and calculating decompression times, making its mechanical granddad well and truly redundant.

That sounds pretty much like the death knell for the mechanical dive watch, but then so did the introduction of quartz movements for mechanical watches in general – but it wasn’t. Quite the opposite, in fact, because now mechanical watches are more popular than ever. Why? Because in a world of technological speed and stress, the simplicity and comfort of out-dated practices comes as something of a reassurance, a comfort. We drive to get somewhere; we walk to relax. We have gas central heating; we fit a roaring wood fire. We have advanced dive computers; we dive with our mechanical watches.

Championing the future of the affordable mechanical dive watch (and affordable they should be; after all, even Rolex released a cheap, non-chronometer version of their Submariner for divers with tighter budgets – the 5513) is Oris, whose dive watches have long offered fantastic value for money. This, the Aquis Depth Gauge, is no exception, offering a solid 500 metres of water resistance and fantastic build for just £2,100. But there’s more to it than that, because the Aquis Depth Gauge has achieved the unachievable: developing an affordable, mechanical Depth Gauge.

There have been watches with mechanical depth gauges before – the IWC Deep One and Two, the Jaeger-LeCoultre Pro Diving Geographic, the Blancpain X-Fathoms, the Panerai Submersible Depth Gauge – but none that adhere to the tradition of affordability.

So how did Oris do it? Well, the mechanics here are purely theoretical, because there isn’t a moving part in sight. Using a channel cut into the double-thick sapphire crystal and a calibrated scale printed on the underside, Oris took advantage of the Boyle-Mariotte law to produce a self-actuating depth gauge. Because gas is compressed proportionally with increasing pressure, the math is quite simple (P=k/V if you’re interested), but it takes a previously unattainable level of precision to cut the channel accurately enough for use.

And it works. Well. As water enters the channel, the cloudy sapphire becomes much darker, and the divide between gas and liquid from which the depth is read is clearly defined. It would take a deep dive (or a night dive) for it to be too dark to read, and that’s probably the point where you should leave nostalgia behind and just use a proper dive computer anyway.

[Note: This is an updated post of a Guest Article published earlier on our website by Gary Robery from]

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