The Seamaster 600 Professional model, also called "PLOPROF", for PLOngeur PROfessional, professional diver, was launched in 1970. It took over four years of study and research to design this watch. The monocoque case is made out of one piece of steel.
Commander Jaques Cousteau used a "PloProf" during a series of experiments at depths of around 500 meters.
The present watch with the winding crown to the right and the bezel lock/release button to the left side in the rarer left-handed version. The "PloProf" is explained and illustrated in Omega Saga by Marco Richon, pp. 136/137.