An extremely versatile sextant. It is particularly suitable for marine use, can be used in aircraft; and is perfect for back yard practice. Its great versatility lies in the fact that it is a combination marine and aircraft sextant. As such, it utilizes both an artificial (bubble) horizon, and a visible (sea) horizon.

The bubble horizon is most useful on land when a see horizon is not available. It does, however, require dark adapted eyes at night since the radium illumination has diminished over the years.

The Mark V includes: a 2x telescopic optical path, a selectable astigmatizing lens, and 4 sun filters. The elevation scale reads from -10° to +100°. A fine scale micrometer drum indicates to 2 minutes of arc with interpolation easily possible to within less than one minute. The sextant is made mainly of brass and aluminum.

The MARK V was manufactured with some models incorporating a chronometric averager. The averager records 60 different readings over a two minute period and supplies an average reading. It was designed for use aboard aircraft where accelerations produce erroneous bubble positions. Sextant weight with the averager installed is 6 lbs., and without the averager is 4 1/2 lbs. Because of the weight penalty, we recommend the non-averaging model for marine use.