The sextant has a black-lacquered brass bell-pattern frame and a wooden handle with a brass-lined hole for the locking mechanism. The automatic clamp and endless tangent screw with a white plastic micrometer drum (“Hezzanith” Rapid Reader Patent) are positioned at the bottom of the index arm. The sextant has four green shades and a Wollaston prism as well as three green horizon shades. Index-glass adjustment is made by a capped square-headed screw and a detached spanner and on the horizon-glass by capstan screws.

Accompanying the sextant is a detached threaded telescope bracket with perpendicular adjustment made by a rising-piece and a milled knob. The telescope is 120 mm in length with an erect image and a wide objective lens (star finder). A second telescope is 187 mm long with an inverted image and two parallel cross wires. An extra drawtube is 96 mm long with an inverted image and four cross wires. The sight-tube is 82 mm in length. Also accompanying the sextant are two green shaded eyepieces, a brush, an adjusting pin, a screwdriver, and a spanner. One part is missing, which is perhaps a battery or lamp.

The instrument has a polished brass limb with an inlaid silver scale from -5° to 130° by 1°, measuring to 124°. It also has a micrometer to 12 arcseconds.

The sextant is contained in a square fitted mahogany box with a patent locking mechanism for securing the instrument when not in use. In the lid is a Hezzanith Instrument Works certificate of examination (not dated) and a repair label for Heath and Co for 1940.

David Stanley Tibbits, the original owner, used it at sea continually between 1934 and 1961, and again in 1977 on board ‘Ayesha’ on a trip from Bermuda to the US and back. For the latter voyage it was apparently lent by the Museum.

The Wollaston prism was used for star observations at night, when the horizon was not well defined. It produces two images of a star, one above, and the other below the original position of the star, with the horizon exactly in between them.