About “Submersible Series” from Panerai Watches

© Erwan Grey All Rights Reserved

© Erwan Grey


It was on a day sometime in March 1936 that the the Royal Italian Navy chose Officine Panerai’s Radiomir for the missions of its frogmencommandos. This new watch was the first professional military underwater watch in history. It combined water-resistance with another feature which made it truly unique in its field: the powerful luminosity in the dark, which meant that the dial was perfectly legible even in the most extreme underwater conditions in which the Italian frogmen operated. This watch is defined in military records as the “Radiomir”, a name identifying the model of the watch, but which was actually the original name of the self-luminous paste developed by Panerai to coat the figures and hands of its watches.

After an initial series of watches with the markers and figures covered with Radiomir paste, Panerai developed a new type of dial, known as “sandwich”. This was even more luminous and became a unique and exclusive feature of its models. The third great innovation took place at the end of the 1940s, with the introduction of the Luminor. The name of the Luminor watch model was taken from that of the new substance also developed by Panerai to make the dial even more luminous.

But the most striking new feature of the Luminor watches was the unique crown-protecting device with lever which made the Panerai watches extremely water-resistant. Also patented like the new name, this crown protecting device with lever is still today, together with the sandwich dial, an exclusive, iconic feature of Panerai watches.





The underwater specialisation of the Radiomir and Luminor models found an impressive synthesis in 1956 with the creation of “L’Egiziano”, a watch exclusively made by Officine Panerai at the request of the Egyptian Navy.
Even larger than the previous models, the diameter was 60 mm, its steel case was fitted with the crown-protecting device with lever, and a large rotating bezel with four studs carrying reference numbers for checking the duration of the dive.

The model “L’Egiziano” was also one of the first Panerai watches with a 8-day mechanical movement: this was still a hand-wound calibre, but its long power reserve considerably reduced the frequency of winding operations, to the great benefit of its water-resistance, which it is thought was to a depth of about 200 metres or more.

While only a few examples of “L’Egiziano”were made at that time, another extraordinary watch which Officine Panerai made in 1988 for the Italian Navy – remained only a prototype model. This prototype was ahead of its time in terms of material: the case was made of titanium, a very light metal but harder-wearing than steel, as well as being amagnetic. With a diameter of 47 mm, the watch was designed to be used at depthsof about 250 metres, but for safety reasons it was strengthened in every part and it was tested, first in a laboratory at a pressure corresponding to a depth of 1,000 metres and then in the sea by divers, without any infiltration or deformation ever taking place.

Officine Panerai also supplied the Italian Navy divers with other essential instruments including wrist compasses, depth gauges and water-resistant torches. The depth gauges were of two types, calibrated for depths of up to 15 or 30 metres, depending on the kind of underwater operations to be undertaken, while the compass had a moving dial with an air bubble to ensure that it was held in an exactly horizontal position when the bearing was taken.

In shape and size, the cases of the compasses and depth gauges were reminiscent of the structure of “L’Egiziano” and they were fastened to the wrist of the frogmen commandos by a large strap of greased leather, like that of the watches. Naturally, beneath the large, curved covers made of Plexiglas®, the visibility of the dials in the dark was ensured by the Radiomir or Luminor paste applied to the reference numbers.

Today Panerai, faithful as always to its own history, presents a collection of Submersible watches of great distinction, water-resistant to no less than 30 bar (~300 metres) and made using the latest generation of modern materials.




All Panerai watches ensure a strong water-resistance in honour of the historic enterprises of the Italian Navy underwater commandos. With the Luminor Submersible, Officine Panerai reinterprets this glorious past proposing a water-resistance of 30 bar (~300 metres) and a function of crucial utility for the divers: a rotating bezel to calculate the duration of the dive.

The bezel rotates in clicks of precisely one minute and only in one direction, to avoid the risk that accidental shocks could misleadingly change the reading of the dive’s duration. The design of the Panerai Submersible watches bezel is inspired by that of the watch created in 1956 by Officine Panerai for the Egyptian Navy known as “L’Egiziano”.

With a sophisticated design to guarantee operations in extreme conditions, all the Panerai Submersible watches exceed the International Standards (ISO 6425) for Divers Professional watches. In fact, the Panerai Submersible watches ensure a water resistance of 30 bar (~300 metres): three times higher than the one imposed by the strict International rules for Divers Professional watches.

The Panerai watches are subjected to a very long series of tests to ensure their extreme water-resistance. The water-resistance test (carried out by a special instrument which subjects the watch to a pressure significantly greater than the guaranteed value) and also the “water drop” test, the thermal shock test, the damp heat test, the salt spray test, the synthetic sweat test and the anti-magnetic test. The Panerai Submersible watches are solid, reliable, resistant watches, faithful to the function for which they were originally made for.


Since the autumn of 1938, the needs of the Royal Italian Navy for underwater watches increased strongly and Panerai supplied the “Radiomir”, which progressively underwent a series of modifications. The major revolution of those years was the way in which the dial was constructed. This went from a single plate with the markers and numerals engraved on it and literally filled with self-luminous paste, to the creation of the so-called “sandwich” dial.

The upper plate of ths ‘’sandwich’’ dial was drilled and the lower plate, which was solid, was covered with luminous substance (Radiomir and later Luminor). The upper and lower plates where joined with a transparent Perspex® disc between them to protect the self-luminous paste perfectly. The watch was so luminous that, during night operations, the underwater commandos had sometimes to cover the dial with mud or seaweed in order to avoid being spotted.

The sandwich construction has been progressively modified since then and is currently made of two superimposed plates. To achieve the optimum level of luminescence and the best endurance over time, today Panerai uses the Swiss Grade A Super-LumiNova®.

© Erwan Grey


The Panerai Submersible watches meet the ISO 6425 standard that classifies a Divers Watch as follows: a watch designed to withstand diving in water at depths of at least 100 metres and having a system to control the time of immersion.

Besides water-resistance, such watches must feature technical specifications including a unidirectional bezel, adequate readability/visibility in total darkness, the presence of an indication, visible in extreme underwater conditions, that the watch is running, here ensured by the running seconds hand at 9 o’clock, and resistance to magnetic fields.

The most predominant requirement in the ISO 6425 standard is water-resistance. All watches must have a water-resistance of at least 100 metres (~330 ft).

The Panerai Submersible ensure a water resistance of 30 bar (~300 metres): three times higher than the one imposed by the strict Internationalrules for Divers watches.

Panerai Divers Professional watches have an anti-clockwise unidirectional rotating bezel with graduated scale for calculating the time of immersion and ratchet clicks at minute intervals. At the start of the dive, the luminous index of the bezel has to be lined up with the watch minutes hand. Once having done this, the duration can be read on the bezel at the end of the dive. The unidirectionality of the bezel rotation avoids accidental manipulation that could interfere with the calculation of the correct diving time.

The case of the Panerai watch is subjected to a long series of tests,carried out at various temperatures and according to procedures whichensure its water-resistance.

Panerai Divers Professional watches are also anti-magnetic watches, that is that they are all able to run with minimal deviation when exposed to a direct current magnetic field of 4,800 A/m (NIHS 90-10).

Divers Professional watches also need to undergo and pass several tests for checking the quality and reliability of all the components. After the case has been assembled, it undergoes its first test for water resistance, to guarantee the protection it provides against the infiltration of dust and humidity. Finally, the strict Panerai standards require a “water drop” test, which is performed by heating the case and placing a drop of cold water or a cold external element on the surface of the crystal protecting the dial. In this way, the possibility that there might be any moisture inside the case itself is eliminated.

© Erwan Grey

© Erwan Grey All Rights Reserved

© Text : Panerai.com
© Photos: Panerai.com / Erwan Grey