For nearly 100 years, water resistant pocket watches and wristwatches had been evolving into more robust timekeepers. However, there was one type of watch that watchmakers hadn’t been able to figure out, the chronograph. The logic is sound; if you intend to make something air tight, best practice dictates starting off with the least amount of holes possible. The more holes, the more opportunity water has to get inside.
1939 Omega CK2077 — Photo courtesy of Christie’s
The 1930s were a breakthrough decade for water resistant chronographs. Gallet kicked things off in 1936 with their Multichron 30 Clamshell, followed by Omega with the reference CK2077 in 1939. Gallet’s Clamshell design was rather unique, getting its name from the way the top and bottom laid together during assembly. The caseback was sealed with a screw at the back of each lug, allowing water resistance up to 100m. As the 1940s came, other brands, like Patek with their reference 1463, got in on the action as well. Like the Clamshell, the general idea was to have one or two rubber O-rings on the inside of the pusher button, around the stem, that keeps water from advancing any further. Simple, yet effective.
The timing capabilities of a chronograph can be very useful for divers, so all these years of missing out on underwater button pressing had to come to an end. Thanks to Omega, and their Seamaster 120, a.k.a. “Big Blue”, released in 1971, the problem was resolved. This was the first chronograph to be fully functional at a depth anywhere near 120 meters. Oddly enough, despite the breakthrough happening over 40 years ago, there aren’t as many fully functional underwater chronographs available today as you may think.
Omega Seamaster 120 “Big Blue” –Photo courtesy of PuristSPro
Omega, you could say, still leads the pack in this category, because all of their Seamaster chronographs rated at 300M or more of water resistance are fully functional underwater. Other notable entrants are Blancpain’s Fifty Fathoms Chronograph (as well as the new Bathyscape), any of Damasko’s chronographs, and Sinn’s U1000. All in all, there are only a dozen or so watchmakers providing this capability.
Internal schematic of Damasko’s patented pusher design
While most of these watchmakers are using a very similar concept for maintaining water resistance, Breitling developed an extraordinarily interesting solution for one of their quartz offerings. The Avenger Seawolf Chronograph utilizes magnetic contacts to trigger the chronograph function. In other words, when the chronograph pusher is engaged, the pusher stem never actually breaches the case. A magnetic signal is sent – the quartz movement is unaffected my magnets – which maintains the airtight seal of the case. Unfortunately, this wouldn’t work for a mechanical watch, as the chronograph requires more force in order to start.
It’s hard to say where the future of water resistant chronographs will go. The pushers are so tiny; there are only so many different things one can do with the technology within. Another limitation is the demand. Mechanical chronograph dive watches aren’t exactly required that often. It would be fair to say most dive watches only have to be water resistant enough to handle the office bathroom’s sink. However, these types of limitations often fail to prevent our endless pursuit of “bigger and better”, and we wouldn’t be surprised if a bold watchmaker develops the next big thing in chronograph water resistance sometime in the near future.
Oh, and, a word of advice. If your chronograph’s user manual doesn’t say anything about using it underwater…don’t use it underwater.
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