When people started exploring underwater, it was easy; from a timekeeping point of view at least. With a couple of sturdy blokes in your dive boat pumping air down to you there was little need to know the time. It didn’t matter whether you were in a diving bell or a suit, someone else told you when you could knock off for a cuppa. But once divers started carrying their own air with them in the late 1940s, knowing how long you’d been down suddenly became a lot more important. It wasn’t just that you needed tabs on how long your air would last on the dive, it was knowing how long you needed to decompress on the way up again. Watches suddenly mattered. A lot.

This presented a problem. Back then, it was tough to keep water out of a watch. The caseback, crystal and winding crown all added vulnerabilities to the case. Neoprene - the synthetic rubber - had only recently been invented and natural rubber sheared too easily to make effective watch gaskets.  So watchmakers tried all sorts of ways to keep water out, from screw-down ‘canteen’ crowns (like a water bottle top) and soft lead caseback seals to double cases.

One of these early waterproofing options, developed in 1956, was the ‘super compressor’ case made by Ervin Piquerez S.A. (EPSA). This new design actually turned a problem into a benefit. The deeper you went, the more waterproof the watch became because of its spring-loaded back and double seal. In fact, an original super compressor would usually be good to 600ft - remarkable at a time when most watches struggled to make 50ft without drowning.

We took the original thinking behind the super compressor case but designed our Aqua Compressor from a blank sheet. Just like an original super compressor, the deeper you dive, the tighter the caseback seal snugs down tighter against its two o-ring gaskets. The water pressure compresses them between the case body and the case back, keeping water out and the movement safe. The difference is that we can use finer machining tolerances, better materials - like modern gasket compounds and titanium - and do away with the spring-loading used in the early casebacks.
This all means that our Titanium Series Aqua Compressors will happily tick away at 1,000ft or 300m underwater and you still get the slim case profile, characteristic double crowns and internal rotating elapsed time bezel of the original watches.

Another update on the original: modern seals (two of them inside the crown tube alone) and engineering are good enough on the Aqua Compressor that, should you forget to screw your winding crown down and swim, everything will still be watertight down to 100m/330ft. The practical depth for even serious SCUBA divers is 130ft - just short of 40m - so you’ve got plenty of margin to play with. Still always worth checking you’ve screwed the crown down before you dive, mind.

We made our first Aqua Compressors, launched back in 2017, from 316L stainless steel. The design is similar but now we cut the 41mm cases from marine grade titanium. This is lighter - some 40% than stainless - but it’s exceptionally tough and corrosion-resistant. In fact, so much so that the metal is used to make key parts for desalination plants. The finish is a mix of a radiating, sunburst brushing on the top surfaces with polished sides and back.
The internal bezel crown is, like the case, titanium but the second crown that winds and sets the watch is classic Farer bronze. Both are deeply knurled, so they’re easy to turn and set. They have the characteristic super compressor cross-hatching on their faces too.
It’s a mark of how far technology has come that not only are these watches good for deeper than almost anyone is likely to dive, but their screwdown backs have a sealed, 1.6mm sapphire crystal; rare on a dive watch capable of serious depth like these.  It’s not only secure but it gives you a splendid view of the automatic Swiss Sellita SW200-1 movement behind it. The domed sapphire crystal on the front is a practically bulletproof 2.2mm thick.

That movement is an unusual engine; it’s a 26 jewel Elaboré grade, adjusted to three positions and there’s no ‘ghost date’ hidden behind the dial and no unused date mechanism adding unnecessary complexity. You’ll see we’ve had the rotor decorated with a wave pattern too.

Since we launched them, the series of Aqua Compressors have been exceptionally popular. We’re delighted that so many people are enjoying them. Their new owners are doing a lot of good too; we donate £25 for each watch we sell to the Hebridean Whale and Dolphin Trust.