The sextant has a brass Admiralty-pattern frame and a wooden handle for containing a battery for scale illumination. The plastic micrometer drum, the pressure clamp and worm wheel, which is damaged, are located on the back of the index arm. The instrument has four green shades and two green horizon shades. The round index glass is non-adjustable and the round horizon glass is moved by capped screws, a square-headed screw and a separate key.

Attached to the sextant is a threaded telescope bracket with perpendicular movement made by a rising-piece and a milled knob. The telescope is 82 mm in length with a star finder, whose lens is missing, and an erect image. A second telescope is 146 mm long with an inverted image. An extra drawtube is 70 mm long. Accompanying the sextant are two green shaded eyepieces and an oil bottle for lubrication. The adjusting key is missing.

The instrument has a polished brass scale from -5° to 135° by 1°, measuring to 135°. Micrometer to 1 arcminutes

The sextant is contained in a square fitted wooden box with an inlaid plate in the lid, which is missing. Inside the lid is a metal frame for holding a certificate of examination, however, the certificate is missing.

The sextant was lost when HMS ‘Royalo’ (FY 714), a Fowey trawler built in 1916 and taken over by the Navy in 1940, was sunk by a mine off Penzance, Cornwall, on 1 September 1940. Divers recovered the instrument in 1962 at a depth of sixty feet, and apparently gave it to Kelvin Hughes, who presented it to the Directorate of Naval Warfare, in 1963.