Jaeger-LeCoultre Deep Sea Alarm US Dial: Unraveling Luminous Variations

We saw some dials coming with luminous material covering the 5 minutes indexes on the Deep Sea Alarm dials, sometimes, while, most of the time, the indexes came without luminous material at all.

Here we are talking of the US version, not the european, to be clear.

Here is, for example, a stunning new old stock specimen. The dial comes without luminous markers:



Mine is clearly in the same vein:



Or this one, sold during a famous auction, in Nov 2011:



Now, the dial with the luminous markers, which belongs to Blomman, now, if I am correct:



For years and years, I wondered if those indexes weren't relumed, to tell the truth, as I saw way much more no luminous dials.

I started to seach in my archives what informations I had on the Deep Sea Alarm, and I found nothing about the US dial.

I just found some interesting informations about different dates:

11th of February 1959: 1st drawing of the Deep Sea Alarm case.

12th of February 1960: 1st drawing of the Deep Sea Alarm dial ( JLC, hence European version, not US ), ref 8239 ( Dial Reference, to be clear ).

Dates of production: From 1959 to 1962. 500 were made in 1959, 1 in 1962, on a total of 1061 watches.

Which means that the 500 first Deep Sea Alarm had an US dial ( Lecoultre ), since the first drawing of the European dial was made in... 1960!

Which means that the 561 other DSAs, produced between 1960 and 1962 were certainly US and European, without any further precision on their respective quantity, but we can guess that a maximum of one third were European, which explains the fact that we really don't often see the Jaeger Lecoultre version.

As I found nothing on the US dial, I asked to the Manufacture if they had something in their archives, and the answer was... Yes... And No.

No, because they don't have any document nor drawing mentionning the US dial.

Yes, because they found... A New Old Stock Dial!

I asked them to put it aside for me to take some pictures during my next visit, and that is what they did!

Here, in " avant première " for your eyes, the new old stock DSA Lecoultre dial:



2 interesting details:

- An information: the 5 minutes indexes are... Luminous!

It is not clearly obvious on the photo, but I have taken it in high resolution, and they are, without any doubt. And not relumed.

- A surprise: The outer part of the dial is grey, when normally, when you refer to the pictures I posted above, it is white.

The luminous in question seems to be tritium, as it is very clear.

So, it seems that these dials were destined to the last years of the production, somewhere between 1961 and 1962, which corresponds to the era where the Manufactures opted for tritium instead of radium.

A fact which can also explain that, to differenciate the radium from the tritium, the outer part of the dial is not of the same color. Both being signed Swiss made, by the way.

One fact: the DSA US dials came, sometimes, with luminous indexes, with the white outer parts, or with the grey, as shown on Blomman's DSA, and on this new old stock dial.

Some guesses about the outer parts, and the meaning of the different colors.

The verso part of the dial shows two things:

The dials of the DSAs come with feet.

They are signed Singer, which is the name of the dial manufacturer, which is a confirmation on an already known detail.



Hoping that it will help you to better know the Deep Sea Alarm, and that it may be of some help if you ever find one,

Best.

Nicolas