The Oyster Case, Symbol of Waterproofness
The Yacht-Master’s Oyster case, guaranteed waterproof to a depth of 100 metres (330 feet), is a paragon of robustness, proportion and elegance. The middle case is crafted from a solid block of 18 ct Everose gold, cast by Rolex in its own foundry. Its fluted case back and the winding crown - fitted with the Triplock triple waterproofness system - screw down securely against the case. The crown guard forms an integral part of the middle case. The crystal, with a Cyclops lens at 3 o’clock for easy reading of the date, is made of virtually scratchproof sapphire. The waterproof Oyster case provides optimal protection for the high-precision movement.
Calibres 3135 and 2236
The new 40 mm Yacht-Master is equipped with calibre 3135 and the 37 mm version with calibre 2236, two self-winding mechanical movements entirely developed and manufactured by Rolex. Like all Rolex Perpetual movements, 3135 and 2236 are certified Swiss chronometers, a designation reserved for high-precision watches that have passed the Swiss Official Chronometer Testing Institute (COSC) tests. Their architecture ensures peerless precision and reliability. In calibre 3135, the oscillator - the true heart of the watch - has a blue Parachrom hairspring patented and manufactured by Rolex in an exclusive alloy. Calibre 2236 is fitted with the new Rolex-developed Syloxi hairspring in silicon introduced in 2014, which offers exceptional chronometric performance. Insensitive to magnetic interferences, both hairsprings offer great stability in the face of temperature variations and remain up to 10 times more precise than a traditional hairspring in case of shocks.
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