The octant has an ebony frame and limb with a black-lacquered brass index arm and fittings. It also has inlaid ivory plates on the crossbar and on the back of the frame, which are both missing. The reinforcement bar is also missing from the index arm. The remains of a tangent screw are mounted on the back of the index arm and a clamp device and clamping screw are missing from the back. The octant has three horizon shades, two red, which are cracked, and one green. The index shades are missing. Index-glass adjustment is made by a screw; however the glass and screw are missing. Horizon glass adjustment is made by a milled knob, a lever, worm gear and a milled clamping screw; however the glass is cracked. The sight vane has two pinholes and a swivelling shutter. The octant is contained in a keystone box, which is badly damaged, with a trade label for Bernard Hennessy, 5 Wind Street in Swansea.

The instrument's inlaid ivory scale is missing. The octant has an ivory vernier measuring to 1 arcminute, with zero at the right.