Longines Watch Markings & Identification Guide

Longines maintains extensive historical archives and may be able to provide production date information based on the movement serial number. This service can sometimes be accessed through Longines customer service, authorized service centers, or the brand's heritage museum in Saint-Imier, Switzerland. This archival access is commonly considered one of the most comprehensive available from any watch brand.

The primary serial number on a Longines watch is typically engraved on the movement itself, which requires removing the case back to access. The case back may carry a separate case reference number. Having a qualified watchmaker open the case is commonly recommended to avoid damaging the watch and to ensure the movement is handled properly.

The winged hourglass is Longines' iconic trademark and is one of the oldest registered logos still in active use, dating back to 1889. It appears on the dial, case back, crown, and clasp of Longines watches. The design has been refined over the decades, and the specific version of the logo can sometimes help approximate the production era of a vintage piece.

Modern Longines watches commonly use ETA movements, often with exclusive modifications such as the silicon hairspring found in some current calibers. Historical Longines watches used a wide variety of proprietary calibers that are well-documented by collectors. The specific caliber is typically indicated on the case back or can be identified by examining the movement.

Authenticating a Longines watch typically involves verifying the serial number against known records, inspecting the movement for genuine Longines markings and construction, and examining the dial for correct logo and printing quality. The ability to check the serial number against Longines' archives is a particularly valuable authentication tool. Professional authentication is commonly recommended for high-value purchases.

The Longines Heritage collection consists of modern watches inspired by significant historical models from the brand's archives. These watches typically combine vintage-inspired designs with modern movements and materials. They can be identified by the 'Heritage' designation in the model name and specific reference numbers. Comparing the case back markings against Longines' current catalog can confirm the model.

Vintage Longines watches can range significantly in value depending on the model, condition, rarity, and completeness. Certain vintage calibers, rare dial variants, and historically significant models command premium prices among collectors. The brand's strong reputation and detailed historical documentation contribute to collector interest. Market values can be researched through auction records and dealer listings.

Longines HydroConquest models are typically rated for significant water resistance, with most models rated to 300 meters, which generally makes them suitable for recreational diving. The specific rating is indicated on the case back and often on the dial. As with all dive watches, regular maintenance and seal checking are commonly recommended to maintain water resistance over time.