The original Submariner was built for divers in the 1950s, so it feels almost natural to want to take its modern descendants into the sea. Yet water resistance is one of the most argued-about topics in the rep world.
Reading through the threads, I find two camps. One says a good rep usually passes a pressure test and people swim with them happily. The other says assume zero water resistance and keep it dry.
Which camp has the better argument? And what does a pressure test really prove?
Related threads: How long does a rep watch actually last, Why does rep lume fade after an hour, the thread on VSF Seamaster 300M long-term.
Camp two is the cautious one, and caution has no downside here. Worst case for camp one is a fogged crystal and a rusty movement. That’s a bad trade for a swim.
Allow me a clarification. On a replica, the rating on the dial is not a tested specification. And as a general rule: any watch, genuine or not, loses its tested water resistance as soon as it has been opened. After that it needs to be tested again. This is stressed several times in the discussions, including by users with watchmaking training.
Thank you, that’s a good distinction: the number printed on the dial versus what has actually been tested.
From the modding side: the culprit is usually boring. In one of those threads, a contributor with watch-repair training sums it up: as long as the case isn’t badly machined, water resistance comes down to gaskets in good condition and properly greased, and a correctly fitted, sealed crystal. Nothing exotic.
I write in English so everyone follows. Also worth knowing: in the community reports, people who test many high-end reps say they usually pass a low-pressure test, but not always. One mentions a leak at the crystal. “Usually” is not “always”.
And there’s the question from one thread: the watch passed a 5 bar test, so is it fine at 3 bar? Some gaskets are said to seal better under higher pressure. Is that real?
Honestly, the thread didn’t settle it, and I won’t invent an answer. The safe conclusion is to test at the pressure you actually care about. Most testers can run several steps.
To add some context: even on genuine watches, a rating like “30 m” doesn’t mean you can dive to 30 m with it. The test is a one-off with static pressure on samples of new watches. The usual manufacturer classification is roughly: 3 atm splashes, 5 atm showering and shallow swimming, 10 atm swimming and snorkelling.
Here’s how I’d put it together, as calmly as I can:
1. The dial rating means nothing until it’s tested. Treat it as unverified.
2. A pressure test proves one thing: that this watch, today, at that pressure, didn’t leak. It’s still the best evidence you can get. Testers pressurise the watch in air first, so a leak shows as bubbles instead of water getting in.
3. Before any test, check the basics:
- Caseback snug, crown fully screwed down.
- Gaskets in good condition and greased. Owners and the repair-trained contributor all point to gaskets as the main failure point.
- No visible damage to the crystal.
4. Match the test to the use. The usual manufacturer classification uhrenfuchs mentioned, roughly:
- Splashes: 3 atm / 30 m
- Showering and shallow swimming: 5 atm / 50 m
- Swimming and snorkelling: 10 atm / 100 m
Community opinion is split. Some report swimming happily after a low-pressure pass, others want 10 bar. If you want to swim, test higher.
5. Re-test after any opening: service, battery, strap work that involves the caseback, anything.
6. Habits that reduce risk: rinse in fresh water after the sea. Some in the threads also advise against showers, because of hot water and direct jets.
And a warning: don’t open the caseback yourself to “check the gaskets” without the right tools. A badly reseated gasket is exactly how leaks start. A watchmaker or repair shop with a tester is the safer route.
Beautifully put. I’ll mark it. If anyone has a test certificate from their watchmaker, I’d love to hear what pressures they used.
Worth remembering: the boring parts (gaskets, crown, caseback) are where the leaks start.