The movement inside this watch carries a lineage that goes to the bottom of Alexandria Harbor.

In 1935, the Italian Royal Navy commissioned Panerai to build a waterproof watch for their elite frogmen the Decima Flottiglia MAS, underwater demolition specialists who rode two-man submersible torpedoes nicknamed "the Pig" into enemy harbors under cover of night. Panerai turned to Rolex for the movement and case. The result became one of the most consequential watches in military history.

On December 19, 1941, six Italian frogmen used these watches to time their raid on Alexandria harbor disabling HMS Valiant and HMS Queen Elizabeth simultaneously. The modern era of special forces warfare was born that night, and Panerai watches were on the wrists of the men who started it.

After the war, when Panerai eventually severed its relationship with Rolex, they turned to Unitas for movements. The Unitas 431 — the caliber inside this watch — is part of that direct lineage. The same Swiss movement architecture that powered the post-war Panerai military watches lives in this Arnex case, remanufactured and running strong.

This is not a watch. It is a piece of the history that created the modern dive watch, the modern pilot watch, and the modern Panerai all of which trace their DNA to those six men in Alexandria harbor in 1941.

Unitas 431, 17 Jewels, manual wind, fully remanufactured. Gold-plated open face case. Blue cartouche dial. Running strong.

A distinctive vintage Arnex open-face pocket watch featuring a blue cartouche dial — one of the more visually striking configurations Arnex produced. The bold blue numerals and cartouche surround give this watch a character rarely seen at this price point.

Movement: Unitas 17-jewel manual-wind, fully remanufactured using all original Unitas components. This is not a replacement movement — it is the original caliber rebuilt to proper running condition. Case: Gold-plated, open face, snap caseback. Clean with minimal handling wear. Dial: White with blue Arabic numerals in cartouche style. Enameled surface in excellent condition.

This watch is for the buyer who wants a functioning piece of Swiss watchmaking history with real visual presence. The Unitas movement alone justifies collector interest.

Ships free via USPS Priority Mail. 30-day returns accepted. 12 years at 100% positive feedback USWatchMasters.