Oliver Smith Jeweler

Panerai Radiomir 3646/1010012

Few military wristwatches embody the history of the World War II as completely as the Panerai Radiomir Reference 3646. Produced around 1945 for the Royal Italian Navy's elite combat divers, this stainless steel Radiomir Type B represents one of the earliest purpose-built military diving watches. Powered by a Rolex caliber 618 movement and housed in an Oyster Watch Co. case, it reflects the remarkable collaboration between Panerai and Rolex during the war.

Unlike many surviving examples, this watch carries an extraordinary layer of documented history. Its engraved caseback links it directly to Captain John Maxted Coltart of the Gordon Highlanders and commemorates the crossing of the Elbe in April 1945, one of the final major Allied operations of the European campaign.

Built for Combat

By the mid-1930s, the Royal Italian Navy sought a wristwatch capable of meeting the demands of underwater military operations. Panerai answered that call by developing specialized instruments for its elite combat divers, known as Gamma frogmen.

The result was the Radiomir Reference 3646, a purpose-built military watch designed for exceptional legibility and reliability in extreme conditions. Its large 47 mm stainless steel case, luminous sandwich dial, and fixed wire lugs made it an indispensable tool during covert maritime missions. To ensure the watch could withstand the harsh realities of combat, Panerai partnered with Rolex, utilizing the proven Oyster case and the manually wound Rolex caliber 618 movement. Together, these innovations produced one of the most significant military wristwatches of the Second World War.

Today, the Radiomir 3646 stands not only as a milestone in Panerai's history, but also as one of the earliest purpose-built military diving watches ever created.

Marked by History

While many military-issued watches have lost their connection to the individuals who carried them, this Panerai Radiomir 3646 preserves an extraordinary piece of its wartime history.

The screw-down caseback is engraved to Captain John Maxted Coltart, a member of the Gordon Highlanders and the 15th Scottish Division. The inscription commemorates his participation in the crossing of the Elbe River in April 1945, one of the final major Allied operations of the Second World War.

Following the successful crossing and the conclusion of the European campaign, Captain Coltart returned home with several souvenirs from the war. Among them was this Panerai Radiomir 3646, a watch whose engraved caseback continues to tell its remarkable story nearly eight decades later.

Unlike many surviving military timepieces, this example remains inseparably linked to a documented historical event, transforming it from a military instrument into a tangible artifact of one of history's defining moments.

Decades of preservation

Nearly eighty years after its production, this Panerai Radiomir 3646 remains a remarkable example of wartime watchmaking.

The watch retains its original Rolex caliber 618 manual-winding movement, housed within the robust Oyster Watch Co. case that defined Panerai's earliest military timepieces. Its distinctive sandwich dial has developed a rich, naturally aged patina, while the fixed wire lugs and screw-down construction remain faithful to the watch's original military specification.

Unlike many surviving examples that have been heavily restored or altered over time, this Radiomir continues to display the honest character earned through decades of history. Every mark, every surface, and every detail contributes to the story of a watch that was built as a tool and has endured as a historical artifact.

Today, it stands not only as a rare collector's piece, but as an enduring reminder of the engineering, craftsmanship, and military heritage that defined Panerai's earliest years.

A Legacy Preserved

The Panerai Radiomir is a surviving witness to one of history's most defining periods—a timepiece whose design, provenance, and enduring originality preserve the legacy of those who carried it through extraordinary circumstances.

From its beginnings as a specialized instrument for the Royal Italian Navy to its connection with Captain John Maxted Coltart and the crossing of the Elbe in 1945, this remarkable watch represents far more than mechanical craftsmanship. It stands as a tangible reminder of innovation, service, and history.

Oliver Smith Jeweler is honored to preserve and share stories such as this, ensuring that exceptional timepieces continue to educate and inspire future generations of collectors.