The trial by repair bill is the way many watch wearers get to grips with water resistance in watchmaking. Essentially the term is all about static pressure rather than real-world experience, and on a brand new watch at that. There are, however, a few useful rules of thumb to be going on with.
Obviously any watch with no water resistance or something as low as 10m should be locked in a waterproof box in case the air gets too humid. At 30m you can splash it but not immerse it and I wouldn’t suggest showering with it until at least 50m. You can only think about swimming with your watch at the 100m mark, though stick near the surface. Anything more and you need 200m or more.
Even then remember that these numbers will go down over time as the seals get worn and the screws get looser. The safest bet? Just keep your watch out of the water.