THE FULL STORY
Before they return to the open air, professional divers heading for the surface after a deep saturation dive must spend time in a decompression chamber, where they breathe a gas mixture containing helium. The tiny molecules of helium, an extremely light and non-volatile gas, infiltrate everywhere in the chamber, also penetrating the watch. During decompression, the helium is unable to escape from the waterproof case quickly enough, creating a pressure differential that could force the crystal out of the watch case. Rolex engineers created a gas escape valve fitted with a spring: it opens when the difference in pressure between the inside and outside of the watch reaches 3 to 5 bars, allowing the helium to escape, thereby protecting the watch.
This particular watch is in pristine condition and appears to be left in its box, protected from the elements. Its box and papers are all original to the watch as it would have been received from the Rolex Boutique.
Model: Yacht-Master Mid
Material: Stainless steel
Dimensions: 35mm diameter; 17.7mm thickness
Lume: Yes, Super Luminova
Caliber: Rolex self-winding caliber 3235
Bracelet/Strap: Rolex folded Oyster 9315 bracelet
Lug Width: 17mm
This 35mm Yacht-Master is in excellent, unworn condition. The case has never been polished. The bracelet is in absolutely pristine condition with a tight bracelet and snappy adjustable clasp. There are no visible scratches on the sapphire crystal, case front, case back, or bracelet.