Italian brand Officine Panerai made watches for the Italian Royal Navy around the start of the 20th century, and the surviving examples of these are very collectible for fans. After about a decade of selling the military the ref. 3646, the navy asked the watch brand for a more heavy-duty version of a diver's wristwatch, and the ref. 6152 and 6152-1 is what Panerai came up with.
This model is often called the "Luminor," after the luminous substance you see on the hands and numerals that Panerai patented in 1949. Luminor replaced "Radiomir," which was the lume that was developed between 1910 and 1915. (The Radiomir nomenclature is still used to mark Panerai watches today.)
There are actually two dial discs here—one coated in Luminor and one black face with cutouts for the numbers and the batons, so the Luminor shows through.
There are only about 100 of these watches known to still be on the market, which makes them especially hot. In 2013 one sold at Christie's Geneva for a whopping $266,000.
The case and movements were made by Rolex, and this example bears a signature by Rolex on both—as well as rare military markings engraved on the back of the case. (Watches supplied to elite warriors like froggers, torpedo riders, and commanders of the Italian navy bore the "Marina Militare" insignia on the dial, as seen here.) A bulky crown protector on the side of the cushion-shaped case is an additional flourish.
This example is in mint condition and has not been polished down to any noticeable extent. The time-only movement is manual, a Role caliber 618, and in great working condition with 15 jewels. The dial is also in good shape, although you'll notice some lume is missing from the four o'clock baton.
At 47mm the watch is a little wide for the time, which means it will wear very well today. It is available for sale for $175,000 at Matthew Bain Inc.