Sinn Navigation Chronograph 903.0423 PL.GL.24h

A rare vintage Sinn navigation chronograph based on the classic Navitimer-style layout. This reference uses the manual-wind Lemania 1877 chronograph movement, configured with a distinctive 24-hour time display, allowing clear AM/PM reading on a single daily rotation of the hour hand. The watch features Sinn’s signature aviation slide-rule bezel and a fully functional chronograph with sub-dials for elapsed timing. The Lemania 1877 is a respected Swiss hand-wound movement known for its robustness, serviceability, and traditional chronograph architecture. This 903 variant (“PL.GL.24h”) represents one of the more specialized executions of the 903 line, combining aviation navigation functionality with the uncommon 24-hour dial format, making it particularly sought after among Sinn and Lemania collectors.