The Rolex Oyster case is designed for you to wear when swimming or diving, lol.
However, as Tobel rightly says, never assume your Chinese Rolex Oyster copy has left the factory in a water tight condition - always assume it hasn’t. And if (for some unfathomable reason) you feel the desire to wear it in water, then get it tested first.
I think it is valid for all replica and vintage watches.