WIRED tested five mechanical dive watches in various underwater environments around the world, from the Galapagos Islands to the Caribbean Sea and the Great Lakes of North America. The watches were worn on the outside of a diving-suit sleeve in temperatures ranging from 3°C to 28°C and depths of up to 45 metres. They were used as backup bottom timers and, in two cases, depth instruments alongside a digital dive computer.
Which ones stood the test of time?
Rolex Sea-Dweller 4000
This year marks the 50th anniversary of the Sea-Dweller, a watch originally built for commercial divers welding pipeline at the bottom of the North Sea.
The gas escape valve on its left-hand side is designed to relieve internal pressure built up from the helium present underwater.
While most of us will never need to test that feature, or the Sea-Dweller’s impressive 1,220 metres of water resistance, overkill is never a bad thing in a dive watch.
Its corrosion-resistant proprietary steel case, scratch-proof ceramic bezel and chronometre-certified movement are a testament to why Rolex dive watches are the standard bearer for the category.
On repeated wreck dives in the Straits of Mackinac, Michigan, the Sea-Dweller’s chunky bezel was easy to grip while wearing a pair of thick gloves. Its blue-hued Chromalight markers, meanwhile, glowed legibly even in murky conditions, and its Glidelock clasp can be extended 20mm for wear over a diving suit.
9/10; £8,350; rolex.com
Omega Seamaster 300 Master Co-axial[image id=”kzVmk2EKe9a”]
It’s the 60th anniversary of the Seamaster 300, and over the years the watch has been worn by everyone from Royal Navy divers to James Bond.
This latest iteration, which harkens back to its earliest ancestor, gets the very best of Omega’s technical know-how.
The Master Co-axial movement that ticks inside is not only chronometre-accurate, but it’s also immune to the damaging effects of magnetism, thanks to a proprietary synthetic hairspring.
So confident is Omega of the movement’s prowess that it presents it under a sapphire display window instead of hiding it away under a protective iron cover. On the front, the rotating timing bezel is hewn from Omega Liquidmetal, which looks like an ordinary alloy ring but is actually poured in place and virtually scratch-proof.
Available in titanium, steel or gold, the Seamaster 300 Master Co-axial is proof that sea watches can evolve to suit their environment.
Over the course of a week diving shipwrecks in Lake Superior, the Seamaster 300 was spot-on, despite the frigid water temperatures and magnetic environment of wrecked iron ore freighters.
The push-button extension built into the clasp easily accommodated WIRED’s 5mm neoprene gloves, and the bezel’s coin edge was easy to grip with numb fingers.
8/10; £4,400; omegawatches.com
Audemars Piguet Royal Oak Offshore Diver Chronograph
The Royal Oak Offshore oozes quality – from its beautifully brushed octagonal bezel that was designed to resemble a vintage diving helmet, to the solid-gold, engraved winding rotor visible through the sapphire caseback.
These features almost distracted WIRED from the fact that the internal timing ring is difficult to set and cannot be manipulated once submerged, or that the chronograph only counts up to 30 minutes, typically about half the length of a good Caribbean reef dive.
But the odds are you’ll be wearing this one to impress while decompressing at the bar later anyway.
And the variety of tropical colours in which it’s available are sure to get noticed, both underwater and topside. With its bright-orange strap matching the mood of the island, the Royal Oak Offshore Diver Chrono was a perfect choice for shallow-reef diving in Curaçao. The inner bezel, however is pretty ineffective as a timing device.
7/10; £21,790; audemarspiguet.com
IWC Aquatimer Deep Three
For years, time and depth have been the two most critical pieces of data for divers. IWC has displayed them both on one watch, starting with its iconic Deep One. The latest in this series is the Aquatimer Deep Three, which incorporates a mechanical depth gauge in the case. Water pressure compresses a spring membrane, which is linked to the depth indicator needles on the dial. One hand shows the maximum depth achieved on a dive while the other shows current depth, both vital to safe diving.
The depth gauge isn’t the only tech on the Deep Three: the rotating timing ring combines an inner flange under the sapphire glass that is manipulated by an outer bezel and linked by a one-way ratcheting clutch on the left side of the case. IWC is known for its Teutonic take on watch engineering and the Aquatimer Deep Three is no exception.
Despite its imposing size, the 46mm case is forged from titanium, which keeps the weight down. Diving with the Deep Three in the Galapagos Islands, the depth gauge matched WIRED’s digital dive computer metre for metre. However, the proprietary quick-release strap mechanism gave cause for anxiety when hovering over the open ocean.
9/10; £14,500; iwc.com
Oris Aquis Depth Gauge
For those of you who can’t fork out for the IWC Aquatimer but still want a depth gauge diving watch, Oris comes to the rescue with its Aquis Depth Gauge. Rather than using a complicated mechanism for measuring dive depth, Oris cleverly takes advantage of Boyle’s law of physics.
A tiny channel bored out around the edge of the sapphire crystal takes in water, which compresses the air inside. The line where water and air meet visibly displays the correct depth on a scale printed on the dial below. With no moving parts on its dial, the watch is virtually foolproof and ingeniously simple.
The mechanical movement and rotating bezel take care of tracking bottom time and an adjustable clasp on the beefy rubber strap can be dialled in for a snug fit over a diving suit.
The Aquis Depth Gauge’s simplicity also means there is no maximum depth indicator on the scale, which prevents the watch from being a true backup depth gauge for serious diving.
During a week of diving around the Caribbean island of Bonaire, however, the Aquis Depth Gauge was a fun diversion, though the channel in the sapphire did require frequent flushing to remove marine grit.
WIRED did like the fact that the watch comes packaged with both a stainless-steel bracelet and rubber strap with changing tool.
7/10; £2,100; oris.ch