Battery-powered, quartz-controlled marine chronometer by Omega, Switzerland. Part of Omega's 'Megaquartz' range. It is so-called because at 4.19MHz the quartz crystal vibrates at a much higher frequency than those in conventional quartz timekeepers.

The fascia of the chronometer can be lifted up on a hinge by releasing the securing screw at the bottom-left. This gives access to the start, stop and advance controls, and the hand-set button, as well as the battery compartment, battery strength indicator and basic operating instructions. The batteries last two years and the chronometer functions in temperatures between -10°C and +60°C.

This chronometer is accompanied by a certificate issued by the Swiss Neuchâtel Observatory dated 3 February 1984 (not shown).

By the 1980s marine navigation was moving towards the increasing use of radio signals but quartz chronometers like this one were still very much in use, especially in smaller craft.