OMEGA SEAMASTER 600. 1ST GENERATION. REF. ST. 166.0077. KNOWN AS "PLOPROF". CIRCA 1970 Professional diver's wristwatch in steel. CASE: large monobloc, asymmetrical, in matte and polished steel. Anti-slip grooved flat back. Red safety push-button to lock the rotating black bezel with luminescent graduation for decompression times. Protected screw-in crown at 9 o'clock. DIAL: dark blue, luminescent baton hour markers, external minute and seconds division. Luminescent hands, white for hours and orange for minutes, central seconds and date window at 3 o'clock. MOVEMENT: automatic, cal. 1002. Dial, case and movement signed. Numbered. DIAM. 55 X 45 mm, thickness: 14 mm. In 1970, the Seamaster line obtained its first "Professional" watch: the "Seamaster Professional 600", also called the 'Ploprof' for PLOngeur PROFessionnel. Production of this reference 166.077 began in 1970. It features a large monobloc case, thanks to which the watch is highly resistant to water pressure, and has been tested at 1370 m. When other manufacturers were working on the helium valve as a means of decompression, Omega created a perfectly impenetrable case in which air could not enter, while leaving a vacuum in the case. CONDITION REPORT: no bracelet Microscratches from use, case has been polished, general wear (flange, scratches on bezel, chips around glass), service push-button, minute hand material missing. See video. The movement works at the time of writing, but cannot be guaranteed. Neither can the individual components, as repairs or restorations may have resulted in the replacement of some original parts. The movement has not been tested for accuracy, and may require service at the buyer's expense. All lots are sold as is, in accordance with the general conditions of sale. No bracelet Microscratches from use. Case polished. Pusher button service. Movement is ticking at time of cataloguing but cannot be guaranteed.