To take warm showers, you have to turn on the water heater .
It is just accross the door of the bathroom, the one with the drop of water (the one on 0 on the photo). After 10 minutes you should be ok. Don’t forget to turn if off afterwards.
The water in Skiathos is not drinkable (well, you can cook with it but it is salty).
Don’t worry, though, we have a lot of sources in town where you can fill up bottles like the ones we have in the kitchen. To go to the closest to the house… follow those directions 🙂
(starting from the house)
I usually bring 6 or 7 bottles in a bag on my back or, if I have company, the easiest way is to bring the whole plastic box and fill everything up.