Mechanism: The Oyster Perpetual began life with the calibre 1030, in 1950. This calibre was also used in several Submariner and Explorer references, 65xx and 66xx. The Cal.1030 was the most popular 18,000 bph movement at the time it was being made. It was noted for its use of a mono-metallic compensation balance and its blue steel Breguet overcoil hairspring.

Cal.1030 also features an unique rotor which is totally different with today’s, two prongs are hollowed on semi-circle, around the outer race engraved with word of “ROLEX PERPETUAL”, beneath is the word of “PATENTED” and the iconic patter of the Rolex crown.

Family Notes: In 1926, Hans Wilsdorf introduced the Oyster watch which used a waterproof case, hence the name. He added "Perpetual" to the name when in 1933 he introduced a reliable automatic self-winding watch. Hence the name means "Waterproof, Self-Winding" in Rolex-speak and generally means the watch is water resistant to a depth of 100 meters.