Legend has it that this watch was issued to helicopter pilots, and that it took its name from the Sikorsky S-58, a helicopter of the same era (first produced in 1953). This notion seemed preposterous to me at first... I mean, this is clearly a diver's watch, not a pilot's watch. But then I learned that the S-58 helicopter was also known as the Seahorse (when configured as a transport helicopter) and the Seabat (when equipped for anti-submarine warfare). Here's a Wikipedia photo of the S-58 at work, dropping a sonar probe to hunt for enemy subs:



Now there's a helicopter whose pilot might have need of a highly water-resistant time piece. So now the connection to the helicopter no longer seems utterly ridiculous to me, just... nonsensical. Come on, it's a dive watch.

The helicopter legend was put to rest, to the satisfaction of many Zenith aficionados, by Tony C., a Zenith collector who posted this response from Zenith to his inquiry regarding the term "S.58" on the O&P forum a couple of years ago:

Dear Sir,

Many thanks for your interest in ZENITH watches.

The collection " S 58 " means S = Super water-resistant up to 150
meters and 58 for the year of launching the model.
So nothing to do with helicopter Sikorsky S 58.

With my best regards.

Marc Roethlisberger

ZENITH INTERNATIONAL SA

Customer Service​

In that same thread, another collector, Celestograph, proposed that the "S" referred to an improved version of the Zenith Sporto model and that the "58" referred to the International Geophysical Year. I can't say that I put any stock in the Sporto connection - especially since a Zenith representative has reportedly stated that the 'S' stands for "Super" - but the Geophysical Year idea has gained some traction with me. I can't think of another reason why a dive watch would feature the year of its introduction so prominently, on both the dial and the case back. And Celestograph notes that other manufacturers such as JLC and Gruen dedicated models to that event.

So, in my personal Zenith belief system, 'S' stands for Super water-resistant and '58' stands for 1958, and '58 may have been included in the model name because it was the International Geophysical Year. Helicopters and Sportos are out.

Rössler (p.147) tells us that the S.58 was introduced in 1958 and that "the army was the target customer, but technicians, chemists and similar professionals could benefit from it," a silly notion based, perhaps, on the silly French advertising copy below, which depicts the early, bezel-less manual-wind S.58 among some pretty reef fish, because it's a dive watch, super-ètanche, supportant 150 mètres de plongée, not a helicopter pilot watch or army watch or chemist watch or technician watch. This was just a smart advertising guy trying to sell a dive watch to science geeks; the more things change, the more they remain the same. (Photo stolen from LouS without permission. )



Rössler goes on to say that Cairelli bought up the entire initial production run of 2500 for the Italian navy... OK, now you're talking...

The first run of S.58's contained a manual-wind Cal 120 with hacking feature. Subsequently (Rössler says two years later), an automatic model was released. The automatic S.58's seem to have been powered initially by the Cal 133.8 bumper movement, and next by the Martel-based workhorse, the 2542 PC. Here is an example of a 2542 PC S.58 recently sold on eBay, posted in another thread in this forum:



Now, on to my watch, which is identical to the example shown in Rössler, with the Cal 120 inside. The movement serial number (very slightly earlier than the Rössler example) dates its production to 1960, probably at the tail end of the initial run of manual S.58's, by which time the bidirectional external bezel had been added. Enough talk... now photos:

 

First off, I bet the guys on that helicopter are really fishing.

Second, what's with that dual regulator arm?

 

to be different

 

That's nice. I did think about trying to slip it into my pocket when I was looking at it for you.

 

Very nice. thanks for sharing this information. Great and rare vintage "primitive era" diver! I guess it is even rarer in this white face version!?

Matt

 

Thanks for sharing....and a interesting read !

 

If any one has one for sale i will gladly buy it. Have been looking for one a long time

 

It just occurred to me that, official explanation of "S.58" notwithstanding, the similarity of the name to that of a sub-hunting helicopter might not have been lost on the executives trying to take some market share away from a certain Submariner. You heard the "inside joke tweaking Rolex" theory here first.

 

Around the same time that Norm scored his very nice self-winding S.58, I came upon an earlier model... from before the rotatable bezel became de rigeur for divers... with its original bracelet. Here are some photos of this first-generation S.58 diver, with a friend from Maine :







The bracelet hinge is branded Zenith and dated "2 over 59" in the Gay Freres style, for 2nd quarter 1959. A Gay Freres product, without the GF stamp?
There is no brand on the clasp - maybe a replacement - but it fits nicely.

There is a case number between the lugs:



I haven't managed to pop the case back off yet, but the manual-wind Cal 120 inside is keeping good time.

Here it is with the subsequent generation, produced a year later:

 

Those S 58s are something...beautiful pieces!!!

 

Thanks. The brick bracelet is very comfortable and sure feels like a GF product. I'm confident that the hinge marked Zenith and the 1959 date is legit... just wondering about the unsigned outer clasp... leaning toward authentic on that too, but I'm biased. I've never seen detailed photos of another example of this bracelet... they seem to be rarissimi.

 

Here is some more reference material... an early, bezel-free automatic S.58, with a cal 133.8 dating to 1959-60, currently listed on eBay with an asking price of €5999.

http://www.ebay.com/ulk/itm/141904706303Purchases made through these links may earn this site a commission from the eBay Partner Network

 

The French provenance is a neat detail. IMO this is one of the more elegant iterations of the S.58.

 

Hi Guys, need your help to see if this is any good for this piece?