Mo Ce Sea

The Mo Ce Sea, which means "lonely sea", is a small open body of water between the Earth Kingdom and the Fire Nation. It extends from the Hu Xin provinces of the Earth Kingdom 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. It serves as a location for major naval incidents and is most notably the home of Crescent Island and Roku's Island. The Mo Ce Sea has seen countless naval battles during the War, and plays host to the incredible Fire Navy Blockade, keeping all outsiders from Fire Nation waters.

History
Aang became accidentally 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, at that time (Aang currently had limited knowledge of the Spirit World and did not know of any other ways 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 incurred a Fire Navy Blockade commanded by a then Commander Zhao. Zhao ordered the blockade ships to attack Aang to which they began catapulting fireballs at the gang. Prince Zuko was also in hot pursuit of the Avatar 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.