Navitimer B01 Chronograph 46

The Navitimer is Breitling's legendary aviation chronograph; It was originally designed as a practical pilot’s watch, combining a chronograph stopwatch with a circular slide-rule bezel that could be used for flight-related calculations. Over time, the Navitimer became one of Breitling’s signature models and one of the most recognizable pilot watches in luxury watchmaking.

The Navitimer’s slide rule is the scale around the dial and bezel. By rotating the bezel and aligning the numbers, the wearer can perform calculations related to speed, distance, fuel consumption, climb or descent rate, and unit conversions. For pilots, this type of tool was especially useful before digital cockpit instruments and electronic calculators became common. Discover the complete Navitimer collection.

A chronograph is an independent stopwatch function built into the watch. It allows the wearer to measure elapsed time without affecting the normal timekeeping display. On a watch like the Breitling Navitimer B01 Chronograph, the main hour and minute hands continue showing the current time, while the chronograph hands and subdials are used to time a separate event.

The chronograph is controlled by the pushers on the side of the case. Typically, the upper pusher starts and stops the timing function, while the lower pusher resets the chronograph hands back to zero. This makes it useful for timing short events, such as a flight segment, a meeting, a lap, a cooking interval, or any situation where you want a precise elapsed-time measurement.

The chronograph and slide rule are two separate functions on the Navitimer. The chronograph is the stopwatch function, while the slide rule is the rotating calculation scale on the perimeter of the dial and the inside of the bezel.

To use the chronograph, press the top pusher to start timing. Press the same top pusher again to stop timing. Once the chronograph has been stopped, press the bottom pusher to reset the chronograph hands back to zero. The main hour and minute hands continue to show the current time whether the chronograph is running or not.

Be sure to stop the chronograph before resetting it. On most traditional chronographs, including watches like the Navitimer B01, the reset pusher cannot be pressed while the chronograph is still running. Resetting while the chronograph is running is only possible on flyback chronographs—which Breitling does not currently produce.

The slide rule is used by rotating the bezel to align the moving scale with the fixed scale on the dial. Once the correct numbers are lined up, the scales can be used to calculate things like speed, distance, fuel consumption, rate of climb or descent, and unit conversions. It works like an analog calculator: the watch does not calculate automatically, but the aligned scales help you work out the answer.