It seems a little strange to me that when Zoi is swimming in the ocean or in the pool, you can answer calls and text messages. It’s strange, but with a special phone it’s possible.
Even if we imagine that you can safely swim with your phone and that the touchscreen works in the water, then another question arises: Where does Zoi store the phone while swimming?
I don’t think the same about this i guess. 
This is a game. Let’s not confuse it with real life.
No one is going to do it like in reality, but it’s not just logical by nature. Imagine that you are swimming, there is only water around, and then the phone rings: Hello! Well, that’s kind of absurd. Moreover, I have a swimming phone in real life and I will say that it is simply unrealistic to use them (touch screens) by their nature.
Waterproof phones exist and are quite portable for use at sea.
