Great Eastern Sea

The Great Eastern Sea is a huge ocean and the largest body of water in Weyard, it's counterpart is the Great Western Sea. The Eastern Sea meets the majority of coastline on Angara, Indra and Osenia and large portions of the coastline of Gondowan and Tundaria.

The Eastern Sea has many large land masses situated entirely within it such as Izumo, Treasure Isle, Sea of Time Islet and the Apojii Islands, as well as three Islets of medium importance. The Eastern Sea also completely surrounds the turbulent Sea of Time (which in itself surrounds the island city of Lemuria). The two are separated by large, impassable reefs. As of the beginning of The Lost Age, the Great Eastern Sea and the Great Western Sea are separated by a continuous mass of land, reefs and ice, due to the re-shaping of the landmasses upon Venus Lighthouse's activation. Only by utilising the Grind Psynergy to (appropriately) grind away large rocks and open a passage through Gondowan Cliffs can a boat sail between the two.

The Eastern Sea is a lifeline of trade and travel for coastal locations such as Champa, Apojii Islands, Alhafra and Lalivero (while Lalivero isn't strictly on the coast, it has ready access to the sea).

At the edge of the world, the Eastern Sea continually spills off the edge creating a giant waterfall called Gaia Falls. Despite this, the ocean does not run out of water.

Story
Felix's party, after having recruited Piers and hence, his Lemurian Ship, set out to explore the Great Eastern Sea. They do this for several reasons, firstly, to acquire the skills necessary to navigate the Seas of Time without falling victim to the swift and dangerous currents located within. Secondly, to find any Psynergy, that might aid them in their quest, most notably from the Elemental Rocks (specifically Gaia and Aqua Rocks). They soon find their respective tasks of entering Lemuria and lighting the remaining lighthouses are impossible, the former blocked by a massive sea beast named, Poseidon, who is invulnerable to all their attacks, and the latter by a jagged rock reef sitting in the middle of the only possible route to the Great Western Sea at Gondowan Cliffs. To fell Poseidon, the group is forced to collect the three prongs of the Trident of Ankohl from various towers scattered across Weyard, which they re-forge into the legendary weapon using Champa's ancient forge. This allows them to enter Lemuria, where the King, Hydros, gives them the Grind Psynergy, allowing Felix's party to finally enter the Western Sea and continue their quest.

Other notable events that the party perform in the Eastern Sea include saving the village of Izumo from the terror of Gaia Rock's Serpent, inadvertently giving the pirate Briggs a means to escape Alhafra and meeting Agatio for the first time (his partner, Karst can be met before the party heads out to sea).

Bestiary
There are many monsters lurking in the deeps of the ocean that can be encountered in Golden Sun: The Lost Age.