I never understood that. Apple claims (for the iPhone Pro Max):
> Rated IP68 (maximum depth of 6 meters up to 30 minutes) under IEC standard 60529
But then, the fine print says:
> iPhone 15 Pro and iPhone 15 Pro Max are splash, water, and dust resistant and were tested under controlled laboratory conditions with a rating of IP68 under IEC standard 60529 (maximum depth of 6 meters up to 30 minutes). Splash, water, and dust resistance are not permanent conditions. Resistance might decrease as a result of normal wear. Do not attempt to charge a wet iPhone; refer to the user guide for cleaning and drying instructions. Liquid damage not covered under warranty.
What is the difference here between being water proof and water resistant?
Is it because water proof is permanent and resistant is time based?
Doesn't that mean that nothing is water proof? A submarine then is also only water resistant, because they have depth limits.
Lastly, they're advertising something, but then stating it's not covered under warranty. Doesn't that go against the Warranty of Merchantability?
iPhone and submarines have different limitations. Submarines have a depth limit because they are (mostly) empty shells at very high pressure and the hull implodes, which is not the case of iPhones. For iPhones, being submerged for extended periods of time water will slowly get in at very low rates, but given enough time it will accumulate to significant quantities to do damage.
