A mahogany deck box fitted with a brass piano hinge and a simple pressed brass sliding catch. The top is glazed with clear plastic in a circular 'porthole' on the upper surface. The box contains a padded, spring-loaded wooden mount for the watch in the lid and lower half. The lower half is baize lined and shaped to the form of the watch. The bottom of the box has a white paper typewritten label 'A Hamilton Navigator's watch, c.1942 / Ch 310 / A79-5'. The chromium-plated nickel, open-face case has a standard winding/setting crown inset with chronograph button and with an oval bow. The convex glass is held in a screw-down, knurled, chromium-plated nickel bezel and the inside of the screw-down back is stamped with the case manufacturer's mark 'KEYSTONE', 'CO' in a shield, 'BASE METAL' and 'K398344'.

The dial is of black chronograph and 43 mm Æ, signed 'HAMILTON' above the centre. The dial has vertical Arabic numerals and small vertical Arabic five-minute figures. There are chronograph minutes in the dial below 12, marked in radial Arabic five-minute figures up to 30. There are chronograph centre seconds with fifth-of-second marks outside minutes. Running seconds are below the centre with radial Arabic, ten-second figures. White painted, steel spade and poker-hands have counter-balanced, white painted centre seconds and subsidiary seconds hands.

The going barrel, three-quarter plate movement is of grained nickel and is engraved on the upper assembly bridge and cocks 'HAMILTON / 19 / JEWELS', 'ADJ. TO / TEMP. & / 3 POS.' and 'MODEL 23'. It is also marked on the main plate, by the balance cock foot 'P25811'. A polished steel index, mounted on the balance cock acts on a lateral screw for fine rating adjustment. The index has a scale under it engraved with 'F' and 'S' for fast and slow. There is a four-wheel train with a going barrel and a centre seconds chronograph drive off the fourth wheel. The chronograph work is all mounted on the surface of the upper plate.

There is a double roller, jewelled and club tooth lever escapement. The impulse roller has a clear jewelled impulse pin and pallets with clear stones. The pallets bank against brass banking pins. The uncut balance is mounted with 16 brass screws around the rim. The flat spiral, white metal balance spring with over coil has an index mounted on the upper surface of the balance cock. The train is jewelled to the third (19 jewels in total) with red stones pressed directly into the plates. The balance has end stones.

The instrument is in fine, almost as new condition, with a few slight knocks to the wooden box.