Mo Ce Sea

The Mo Ce Sea, which means "lonely sea", is a small open body of water between the Earth Kingdom, the Fire Nation and the United Republic of Nations. It extends from the Hu Xin provinces of the United Republic to the Crescent Island and from the Fire Nation islands to the western coast of the Earth Kingdom. It is connected to the western lake located southwest of Ba Sing Se.

The sea served as a location for major naval incidents and is most notably the home of Crescent Island, Roku's island, and the seaport village, an important Earth Kingdom port. The Mo Ce Sea has seen countless naval battles during the Hundred Year War and played host to the incredible Fire Navy blockade, keeping all outsiders from Fire Nation waters. It also connects to Republic City through an inlet known as Yue Bay.

History
Early in Team Avatar's travels, Aang accidentally became trapped in the Spirit World. While in the Spirit World, he was confronted by Roku's animal guide, a dragon named Fang, who took him to the Fire Temple and communicated with him spiritually, advising him to visit the temple on the winter solstice which happened to fall on the day after. The winter solstice was the only time when Aang could speak to Roku in the temple; due to his limited knowledge of the Spirit World at that time, Aang did not know of any other way he could communicate with Roku.



The following day, Aang and his friends journeyed across the Mo Ce Sea in order to reach the temple before sunset. They encountered a Fire Navy blockade commanded by then-Commander Zhao. Zhao ordered the blockade ships to attack the Avatar by catapulting fireballs at the gang. Prince Zuko was also in hot pursuit of Aang and chose to cross the Mo Ce Sea into Fire Nation waters despite having been banished from the Fire Nation. Aang, Katara, and Sokka managed to evade the blockade and reached the temple in time for Aang to talk to Roku.

Amon and Tarrlok went across the sea to escape from Republic City and start a new life. Here, Tarrlok blew up their boat, killing them both.

Trivia

 * After the Hundred Year War, a pro-bending team named the Mo Ce Mongoose Lizards was formed.