Aura

Like a voice, a scent, and a physical appearance, a person's aura is the idiosyncratic feeling created by the presence of water in their body, detectable by those with a strong water sense. Its detailed shape varies depending on the individual's state of mind and health. Most people have just enough watersense to affect the boundaries of their own auras; however, it is impossible to fundamentally change their feel. Auras are as distinct and personally identifiable as fingerprints.
Large groups of people can be considered to have a collective aura. When in close proximity, individual auras will sometimes mirror each other, effectively spreading a strong emotion from person to person.