Using your Sony Xperia Z5 in the pool to take a photo will void the warranty83
Ever since Sony launched the Xperia Z lineup of Android-based smartphones and tablets, the company has often advertised these devices as dust and waterproof. In fact, the company's promotional material often suggested that the Sony Xperia Z smartphones can be used under water, and some of the material showed the devices taking pictures under water. Here are a few examples:
More recently, however, it looks like the manufacturer has changed its stance on using its waterproof smartphones and tablets while completely submerged.
Right after, Sony links to a dedicated page on its website that details the company's stance on water and dust protection. Sony states that the user "should not use the device underwater, such as taking pictures". Exposure to drops of rain, spilling drinks on the device, and using the phone with wet fingers are all acceptable, but the company repeatedly advises not to use the devices underwater.
Sony notes that the IP ratings of these smartphones guarantee that the phones remain functional after being submerged underwater in strictly controlled experiments, where the phone is carefully inserted in a tank, and then carefully removed after a certain amount of time. Pressure levels are likely to skyrocket if you use the handset while swimming, and the phones are not guaranteed to last in these harsher conditions.