Quick answer
A fake ultra deep 6000m is a first copy watch sold with the 6,000 m depth claim copied from the Omega Seamaster Planet Ocean Ultra Deep. The number is a marketing line. Replica factories do not pressure test cases, so a new first copy holds water out to about 30 m in the best case. Wear one in a pool and water can reach the movement.
What 6,000 m means in numbers
Seawater pressure rises about 1 bar for every 10 m of depth. At 6,000 m the load is about 600 bar, or 60 MPa. A 32 mm sapphire crystal under that load carries close to 5 tonnes of force. The original Ultra Deep uses a 5.2 mm sapphire crystal and a grade 5 titanium case to survive it.
ISO 6425, the divers' watch standard, requires a test of every watch at 125 percent of the rated depth, plus a 30 minute immersion check. A 6,000 m rating means a 7,500 m test on each unit.
The watches that carry the number
- Omega Seamaster Planet Ocean Ultra Deep, 2022, 45.5 mm case, grade 5 titanium, 6,000 m / 20,000 ft.
- Rolex Deepsea Challenge, 2022, 50 mm case, RLX titanium, 11,000 m / 36,090 ft.
- Rolex Deepsea, 44 mm case, 3,900 m / 12,800 ft.
What first copy listings claim
Most listings on first copy sites put "6000m" in the title and stop there. Few list case thickness, crystal thickness, gasket material, or a test report. Photos show a screw-down crown, a caseback gasket and a helium escape valve. None of those parts prove a seal.
Real limits on a first copy
Sealing on a first copy changes from batch to batch. Field results:
- Rain and hand washing: no water entry in most cases.
- Swimming at 1 m to 3 m: water entry is possible.
- Snorkeling and diving: water entry is probable.
- Shower and hot tub: heat expands the seals, then water enters as they cool.
No replica factory owns a pressure chamber. The test rig costs more than the watch, and each test takes 30 minutes or more.
If you want water resistance
- Ask the seller for a test result in bar, not a depth figure.
- Take the watch to a local watchmaker and request a dry test at 3 bar to 5 bar before you swim.
- Replace case gaskets and add silicone grease if the test fails.
- Keep the crown screwed down and leave the caseback alone.
Buying checklist
Treat the 6,000 m line as a style reference, not a spec. Check case diameter (45.5 mm on the original), lug to lug length, weight and movement. A titanium case at 45.5 mm feels light. A steel first copy of the same size weighs more, and that gap shows on the wrist. Ask for close photos of the crown threads and the caseback engraving before you pay.