Recently, our editors went 11 feet under water to test various divers’ watches for legibility, ease of use, and toughness in actual diving conditions. One of these watches was the Replica Omega Seamaster Planet Ocean 600M Co-Axial.
The Omega Seamaster Planet Ocean 600M Co-axial boasts very high-quality, well-crafted components, which contribute to its considerable sturdiness. The case, made of titanium, suffered only the slightest scratches during our test dive: The faint blemishes were almost impossible to detect on the sides of the case, which are satin finished. The bezel remained unscathed because it has ceramic inlays like those on the bezel of another watch we tested, the Oris Tubbataha. The numerals and indices on the Omega’s bezel are made of “liquid metal,” a metal alloy with such a low melting point (400 degrees Celsius) that the molten metal can be pressed into the bezel’s notches without damaging the surrounding ceramic. Steel alloys ordinarily used for watches have a hardness between 200 and 240 Vickers, but liquid metal is harder: 600 Vickers. The ceramic used for the bezel is even harder (1,200 Vickers), so after the liquid metal has been pressed into the notches, any excess alloy can be scraped away without marring the ceramic. Omega’s combination of ceramic and liquid metal results in a very hard and finely crafted dive-time ring. The ceramic on our test watch has the same lush blue color as the carefully crafted dial and the rubber strap. With its organic-looking surface and contrasting stitching, the rubber strap looks like leather and makes an elegant impression. It has a sturdy titanium clasp with two safety buttons and an embossed Omega logo.
The bezel is easy to turn, provided the wearer’s diving gloves are no thicker than 3 mm. The rotating bezel clicks cleanly into each of its half-minute settings without wiggling. User-friendliness is unfortunately not as good under water as it is above. Reading the dive time is extremely difficult because the bezel doesn’t provide enough contrast. But even the time of day can be hard to make out: The hour and minutes hands, both with arrowheads, are so similar that they can be difficult to tell apart in turbulent or murky water. If you descend to darker depths, the luminous paint on the hands is too sparse to assure absolute clarity.
The paint itself shines very brightly and the minutes hand, unlike all the other displays, glows yellow rather than green. The indices are nice and wide, too. These features combine to make the time very easy to read on land both day and night. The poor legibility only occurs under water, so the watch’s legibility received an overall rating of “good” in our test. Another shortcoming – and one that we found on nearly all of our test watches – is the crystal’s inability to compensate for the peculiar way that light refracts under water. The front crystal is highly reflective: If you turn the watch even slightly, the dial you could read a moment ago can change into a totally reflective surface.
This effect disappears entirely when you return to the water’s surface, where you can view the face from the side to enjoy the three-dimensional look of the dial, which has applied indices and an applied logo. We weren’t so happy with the black date disk: It’s the only element that doesn’t match the blue of the rest of the watch. The date display can be reset backward if necessary, rather than having to move it dozens of days forward. It jumps forward to tomorrow or back to yesterday as necessary when you set the hour hand forward or backward in hourly increments. The watch contains Omega’s own automatic Caliber 8500, which deserves kudos for its distinctive embellishments and modern construction, including a balance bridge rather than a balance cock, a freely swinging hairspring, and four regulating screws on the balance. The balance spring is made of silicon. Download the full review here.