01Water resistance is a product test claim
The marking and applicable test standard describe the exact product's water-protection pathway. Real use can also be affected by buttons, seals, temperature, ageing and the manufacturer's operating instructions.
02Dive capability needs explicit documentation
For scuba or freediving use, look for the exact model's documented depth rating, dive modes, sensors, algorithm and operating instructions where applicable. Never infer these from a generic ATM or metre marking alone.
03Use the device manual as the controlling source
The manufacturer's current operating limits and warnings take precedence over a category page or comparison article.