From Official Wiki of the Renaissance Kingdoms
The water flask is:
- an event food:
- 1 point of hunger
It has a weight of 3.
- The water flask is empty when purchased. To fill it, simply use it in a village.
- It is possible to use it even when your character has already filled their hunger bar.
- If your character is the leader of an armed group and has chosen to travel, they are temporarily considered to be on a node and can use the flask. Other group members cannot use it if they have it.