Sony used to run an ad showing the Xperia phone being used under water. And other manufacturers have have advertised "waterproof" phones. I think they all backtracked from that after having to process large numbers of water damage warranty claims. It still is possible to get water damage by leaving a port cap open. But it's hard for a manufacturer to call the customer a liar and and deny the warranty claim. It's easier just to have a policy of not covering water damage and then letting the ones through that are actually legit.