Omega Seamaster Planet Ocean 600M Co Axial Master Chronometer 39.5mmvsYema Skin Diver CMM.20

The Omega Seamaster Planet Ocean 600M Co Axial Master Chronometer 39.5mm is praised for its excellent finishing and handsome, easy-to-read dial with good lume. Owners find the 39.5mm size suitable for smaller wrists, though some describe it as a chunky or heavy piece. The Co-Axial movement is noted for potentially increasing service intervals. Opinions are divided on the case proportions, with some finding them strange or awkward due to the 14.5mm thickness, while others appreciate its substantial build and comfortable bracelet with a useful micro-adjust clasp, though one reviewer noted a lack of micro-adjustment on the steel bracelet. The "Summer Blue" dial is considered pretty, and the watch retains its 600m water resistance and helium escape valve. One reviewer found a specific brown ceramic and gold combination visually jarring.

The Yema Skin Diver CMM.20 is lauded for its vintage aesthetic, 39.5mm case size, and well-proportioned handset with sharp indices. Owners praise its textured cream dial, French tool watch elegance, and the smooth winding feel of the in-house CMM.20 micro-rotor movement. The fully brushed bracelet with toolless micro-adjust clasp is considered Yema's best yet. Accuracy readings range from -3/+7 seconds per day to approximately 0 to -10 seconds per day. Some reviewers noted questionable finishing on a prototype's hour hand and a rattly, stamped clasp. The watch's pricing has been questioned by some due to brand QC reputation, and its extended lug-to-lug may challenge smaller wrists. On balance, owners and reviewers appreciate the Yema Skin Diver CMM.20 for its vintage styling and improved bracelet design at its price point.