Yes, it's probably something that has to do with rivers because in Portugal we have a word "ria" which means river and it's pronounced the same way as Rhea. And since Portuguese language has its roots in Latin and Greek...
In the film Solaris (both Tarkovsky and Soderbergh versions), the troubled but beautiful wife of the protagonist is named Rheya. I think that's a lovely variation of this beautiful name.
My grandma's name is Marie. But she went by Rhea when she was a teenager. My fiancee says he doesn't like the name Rhea because he thinks it's a name that can be teased easily, i.e. Rhea has diarhea. Yeah gross. But I think this can also be spelt Ria, and be short for Maria, Gloria.
I first heard of this name in the movie Solaris and have loved it ever since. It is one of my favorite female names, though I have always thought it was pronounced ray-ah. It is extremely feminine without being fluffy, pretentious or airheaded sounding. To me it sounds almost mysterious but delicate.
I love this name if it is pronounced "Ray-ah", mostly because it sounds prettier this way but also as a way of avoiding that awful "diarrhea" nickname.
Excuse me, but I have the name Rhea for my middle name. Yet, I pronounce mine much like the name Rae, for it's also short for Rachel. My name was meant to honor my grandmother who holds the name Rachel. Yet, my family has the most unique combinations of names, we spelled my name R-H-E-A, Rhea, or Rae.
Etymologists have also suggested that it comes from ερα meaning ground—with metathesis (switching) of the first two letters to get ρεα. It has also been suggested that the name is related to the Greek "pomegranate" (ροα) and is Indo-European in origin.
I really like it. I prefer it pronounced REE-ah, though RAY-ah wouldn't be a bad sound, either. When I think of someone named Rhea, I think of a tall, beautiful woman with long blond hair, amber eyes, and caramel-colored skin wearing a long gold dress standing in the sunset. I always think of gold whenever I hear this name.