Cassens & Plath Sextant BOBBY SCHENK black, Full-view mirror

‌This model was developed together with the famous circumnavigator Bobby Schenk.

This model is well suited for sailors to carry out solar and twilight observations, as it is equipped with a full-view mirror.

In addition, there is a scale on the barrel screw with which the index error can be corrected. This index correction on the sextant was developed by Bobby Schenk.

You can choose between a rough case and a wooden case. You can also have your sextant engraved with your name on request.

Please note: The artificial horizon does not fit into the rough case together with the sextant. Here we recommend the wooden case, in which an additional holder is attached.

Sextant frame and construction

The frame is made from a 5.5 kg brass plate, which is milled to produce a frame weighing approx. 0.6 kg. Once the milling work is complete, the frame is heated in a furnace, straightened, ground and engraved. The individual components are then assembled. Once completed, the sextant consists of over 100 individual parts, most of which are manufactured in-house. All components are assembled and adjusted by hand. Each sextant is tested after manufacture and a quality certificate is issued.

Full-view mirror

The sextant is equipped with a full-view mirror. It is half-silvered and therefore semi-transparent, which means that half of the mirror can be used to look in the direction of the horizon, while the other half reflects the line of sight in the direction of the index.

This has the advantage that the celestial body can be kept in view more easily even in rough seas and that the celestial body and the horizon are always in view at the same time. This simplifies measurement. The partially transparent mirror coating slightly reduces the brightness of the horizon image, which can make observations at dusk more difficult.

Index adjustment

The BOBBY SCHENK sextant has an index adjustment on the drum screw. There is an extra scale on the drum screw where the index error can be corrected, so this error does not need to be taken into account in further calculations.

The index error can also be adjusted on the horizon mirror. This has the advantage that the index error is corrected precisely and the measured values can be used directly without further corrections. This simplifies navigation and reduces the risk of calculation errors.