The Xperia Z is a pretty spiffy flagship phone, and tough as well, thanks to its IP55/IP57 Ingress Protection rating. But now there's a more specialized model coming, the Xperia ZR, designed specifically for waterproof functioning in even wetter environments. The new phone is manufactured to the higher IP55/IP58 standard, meaning that it can be safely submersed in 1.5 meters of water for up to 30 minutes.
The Xperia ZR roughly follows the Z's design, getting rid of some of the slim lines and premium materials for the sake of its more waterproof chassis. It looks a lot like the slightly down-market ZL, in fact, with a plastic body.