This one comes from the SHOM.
He'd been developed for the French navy which chose it for its fleet from among 36 other competitive products after one year of testing at sea under the most severe conditions. This high precision instrument (less than one second of deviation per month) successfully passed the most rigorous scientific tests at the Neuchatel Observatory: temperature variations, thermal shocks, magnetic fields, etc. Which after 47 hours of examination earned it the official title of quartz "Quartz Marine Chronometer", with certificate.

Two-body, mahogany deck box with brass-bound corners. Movement and dial in a hinged brushed aluminum case: the front inscribed: “Service Hydrographique et Océanographique de la Marine”, a brass plaque numbered “410”, an electronic connection “1Hz – 1 V” and a locking knob. D. Black with painted white baton indexes, outer minute/seconds divisions on a raised chapter ring. White “baton” hands. M. Cal. 1525, electronic, with switch to operate at double rate, power reserve switch with indicator, frequency regulator. Dial and movement signed. Dim. 21 x 17 x 12.

Inside, there an official rate book. On the first page there's the serial number, Omega, frequency and the date of purchase (May 1983). This book is signed by the technician of SHOM. There an other book inside entitled "OMEGA - Garde-temps de marine - quartz haute fréquence 4,19 Mhz - Cal.1525". Inside, there are technicals specifications, description and how it works.

Launched into the market in 1980 as the "Omega Megaquartz Marine Chronometer", it is thought that less than 1000 pieces were made out of which the majority was delivered to the French Navy. Swiss Government also used the Megaquartz as official gift and examples were given to King Carl Gustav of Sweden, French President Mitterrand and King Hussein of Jordan. The city of Geneva presented it to Presidents Reagan and Gorbachev during the America-Russian summit in 1985.

If you've need more details or pictures, ask me.
Asking price: 3 000 € + shipping cost.

Best regards.