There is a thin line between Sony Xperia Z being waterproof and warranty being void due to immersion in water. The waterproof condition works only if the port seals are closed and are in place. So, if the owner takes the phone into a moisture-ridden environment with the port seals open and is not using it as intended, the warranty for Sony Xperia Z will be void. The phone has durable tempered glass on the front and back, there is also an anti-shatter film on the front and back which makes the phone resistant to wear and tear. The frame is made of glass fiber polyamide which is used as metals in automobile parts
Sony claims that in order to get the high IP55 & IP57 rating, they submerged Xperia Z under water for 30 minutes. They also say that the phone is resistant to water jets. The glass makes Xperia Z waterproof, there are small holes from where water can seep in. These parts are covered with waterproof material.
Sony Xperia Z is waterproof up to 1 meter and 30 minutes. So up to half an hour, you can keep the phone in water and it will still work.
Sony has mentioned this on their website.
“ In compliance with IP5/7 and IP5X, Xperia Z is protected against the ingress of dust and is water resistant. Provided that all ports and covers are firmly closed, the phone is (i) protected against low pressure jets of water from all practicable directions in compliance with IP 55; and/or (ii) can be kept under 1 metre of freshwater for up to 30 minutes in compliance with IP 57. The phone is not designed to float or work submerged underwater outside the IP55 or IP57 classification range and should not be exposed to any liquid chemicals. If liquid detection is triggered on the handset or battery, your warranty will be void.”
In other words, the warranty of Sony Xperia Z is void if liquid detection is triggered. If the ports were all sealed firmly at the time and yet it suffered damage, despite their claim stating evidently that such usage should not spoil it, one can argue that the sealing was faulty, and hence the goods sold were not meant for their proposed purpose (as laid out in the Sale of Goods Act of 1979).
Some people have reported that after submerging the Sony Xperia Z in water for about a minute, the speaker went quiet and even after two days, the sound was not audible. The speaker is supposed to go silent as a temporary cushion to prevent damage to the speaker membrane.Under every port cover, are little moisture indicator tabs that turn pink or red if activated. The tabs normally should activate when there is moisture seepining. But if these tabs are not activated, they will be covered under Sony, under warranty.
The standards of water resistance for Sony Xperia Z apply only to fresh water and they do not recommend immersing the device in the sea water. Salt water is heavier than sea water which means there will be higher pressure at a particular depth compared to fresh water. In case, if the phone did fall into sea water, you may have to rinse it in fresh water because if salt water dries, it may leave tiny salt crystals that could damage the sealing and seep under the buttons damaging the hardware.