The Richard Mille RM 055 Bubba Watson Grey Boutique Edition is a 50mm luxury timepiece featuring a highly skeletonized design. This limited edition of 100 pieces is distinguished by its all-grey monochromatic aesthetic, utilizing a tri-part case construction. The bezel is crafted from ATZ, a high-density ceramic known for its scratch resistance and color stability, while the case middle and back are constructed from grade 5 titanium with a protective rubber coating. This combination of materials ensures the watch is exceptionally lightweight and durable, specifically designed to withstand the high-impact forces associated with professional golf.
At the heart of the timepiece is the manual-winding Caliber RMUL2, a movement that weighs just 4.3 grams. The architecture is defined by extreme skeletonization, with the baseplate and bridges made of PVD-treated grade 5 titanium to provide maximum rigidity and surface flatness. To enhance its sport-driven performance, the movement is suspended within the case by four elastomer shock absorbers, allowing it to withstand accelerations exceeding 500 Gs. The watch features a variable-inertia balance wheel for long-term accuracy and a double-barrel system that improves torque stability over its 55-hour power reserve.
General reviews of the RM 055 frequently emphasize its remarkable ergonomics and “disappearing” feel on the wrist due to its lightweight construction and curved tonneau shape. Collectors and enthusiasts often praise the technical visual depth provided by the transparent sapphire crystal on both the front and back, which offers a clear view of the complex, suspended movement. While it is highly regarded as a pinnacle of material innovation and engineering, some critics note that the extreme skeletonization can make the time-only display difficult to read at a quick glance and that its water resistance is limited to 30 meters.