Quick answer
Four checks catch most problems on a Planet Ocean Ultra Deep 6000M replica: case thickness, the Manta lug strap connection, dial and bezel alignment, and caseback engraving. The genuine watch measures 45.5 mm across and 18.12 mm thick in Grade 5 titanium. Replicas rarely match that thickness, and few reproduce the side-mounted strap bar in a way that holds tight. Movement and lume come second.
Before you start
- 10x loupe or a macro lens for phone photos
- Digital calipers, or a ruler with millimeter marks
- Kitchen scale that reads single grams
- Reference photos of the genuine Ultra Deep on screen
- A dark room for the lume test
Inspection steps
- Measure the case width at the widest point, from 9 to 3.
- Measure the thickness from the caseback center to the top of the crystal dome. Expect roughly 18 mm. A reading under 17 mm means a slimmed case that will not sit like the real one.
- Weigh the head. Titanium reads light for its size. Steel copies of the same case add 30 to 50 grams.
- Look at the lugs. The Ultra Deep uses Manta lugs, which are flat and shallow, with a bar running through the case sides instead of a standard spring bar. Check that the bar sits flush on both sides and that the strap has no side play when you pull on it.
- Turn the crown at 3 o'clock. It should be conical, screw down with a smooth thread, and stop without grit.
- Check the helium escape valve at 10 o'clock. It should be conical and sit proud of the case, not flush.
- Rotate the bezel. Count the clicks, listen for even spacing, and confirm the triangle lands on 12 with no drift. Check for up and down play by rocking the bezel edge.
- Study the dial print under the loupe. Compare the logo, the model text, and the depth rating against your reference photos. Look at the marker feet, the rehaut, and the spacing between the text lines.
- Wipe the crystal with a microfiber cloth and tilt it toward a lamp. A domed sapphire with inner anti-reflective coating goes dark at an angle. A milky ring at the edge points to mineral glass or a single-layer coating.
- Flip the watch over. The caseback should carry a clean engraved depth rating and the correct motif for the reference you are comparing to. Laser etching that looks shallow or double-cut is a common flaw.
- Charge the lume with a phone light for 30 seconds, then kill the lights. Glow should be even across every marker and both hands, with no dull spots.
- Check the movement. Ask which caliber sits inside. Common options are a Miyota 9015, a clone ETA 2824, or a lower-grade Chinese automatic. Wind it, set the time, and listen for rotor noise.
Common tells of a low-grade copy
- Thickness under 17 mm, which throws off the side profile
- Standard lug holes cut into the case instead of Manta lugs
- Bezel insert with printed markers instead of the Liquidmetal look
- Marker at 12 that does not line up with the crown
- Caseback engraving that is off-center or too shallow to read
After the inspection
No replica carries a real 6,000 m depth rating. The gaskets, caseback threads, and crystal seating are not tested to that standard, so treat the watch as splash resistant at best. If you plan to swim with it, take it to a watchmaker for a pressure test first. If the test fails, keep it dry and enjoy it on land.