The Water Tribe (水底の民 Suitei no Tami), sometimes referred to as the Blue Tribe, were the center of civilization and created advanced forms of culture and technology. An ancient civilisation in the Gagharv universe introduced in The Legend of Heroes III: Song of the Ocean.
It is said they ruled the world after the gods Bardus and Octum fell into their slumber. They had the ability to change sound into power by creating and mastering the art of Resonance magic. According to Weltluna legend, those who wielded the power of Resonance magic after many years of training could use instruments to turn music into powerful forces. Negative energy known as the Wave of Raual created by their magic caused a great catastrophe and created the split between the lands otherwise referred to as the Gagharv. All existence of the Blue Tribe suddenly vanished about 900 years ago and now remains as nothing more than a legend.