Spirit of Water is the twenty-ninth optional quest. It can be obtained by speaking to Priscilla, who is located just north of Kalm. However, the quest cannot be obtained unless the player has at least one class that is Level 50 or higher. First, Priscilla asks the player to bring her Water Materia. She will accept Water, Watera or Wateraga Materia, but will take the materia with the lowest level if multiple instances are in the player's inventory. Water Materia can be obtained in multiple ways, most prominently by completing the quest Hydra Egg. Next, she asks the player to retrieve the Tiara of the Deep by defeating Vodyan the Sea Giant. Vodyan can be found at the connection between Naga Islands and the Ancient Forest. Returning the Tiara of the Deep to Priscilla rewards the player with 3000 EXP and 8000 Gold.
If the player has defeated Ultima Weapon when completing the quest, the quest The Strongest Eidolon is automatically acquired. Otherwise, the player must return to Priscilla after defeating Ultima Weapon to obtain it.