[Q] Waterproof Information topic

Hello, I had this smartphone for a month, but I read on the internet that, when the Xperia Z2 is submerged under water, the camera becomes blurred.
I want to know if this problem has come on all devices, or only on bad product. I followed the tutorial to find if my device is isolated pressure sensor (the number changes when I press my device).
So someone used Z2 underwater? How did you find problems after use?