The Ceres Ocean is a vast body of water located in Strangereal's northern hemisphere. It is connected to the Arctic Ocean in the north, the Pacific Ocean to the south, and the Fuscum Sea to the northwest. The Ceres Ocean is bordered by three nations: Yuktobania, Osea, and Estovakia.
During the 2010 conflict between Osea and Yuktobania, the Ceres Ocean became an important battleground for the warring superpowers and the final resting place of numerous naval vessels. During the lead up to the war, several skirmishes took place over the Ceres Ocean between Osea and a number of unidentified fighter and reconnaissance aircraft.
Following Yuktobania's declaration of war on September 27, Sand Island Air Force Base, located in the Ceres Ocean, became Osea's first line of defense against attacks from the west. That day, Yuktobania launched a surprise attack on St. Hewlett, Osea, the home port of the 3rd Osean Naval Fleet. Despite encountering fighters, bombers, and a Yuktobanian naval blockade, the flagship carrier OFS Kestrel escaped the harbor into the Ceres' open waters. Later that evening, Yuktobanian fighters and bombers crossed the Ceres and launched an air raid on Sand Island; Wardog Squadron repelled the attack and maintained control of the island.
Three days later, on September 30, the 3rd Osean Naval Fleet's aircraft carriers (Kestrel, Vulture, and Buzzard) passed through the Ceres and entered Eaglin Straits to regroup in the inland Bennion Sea. Several days later, on October 4, Yuktobania attempted an invasion of Sand Island, and a heated battle broke out over the Ceres between Osean defense forces and the Yuktobanian naval units. As a result of the engagement, the wreckage of the underwater carrier Scinfaxi now lays at the bottom of the Ceres.
On October 31, Osean naval forces and landing units, escorted by Wardog Squadron, crossed the Ceres and successfully established a beachhead on Yuktobania's eastern Bastok Peninsula. As the invasion progressed, Osean forces were dispatched across the Ceres to reinforce the inland offensive, while Yuktobanian fighters headed east to perform raids against Osean targets.
Almost two weeks later, on December 19, the Arkbird descended into the upper atmosphere over the north Ceres in order to adjust its course and perform a nuclear attack on Okchabursk, Yuktobania. However, the newly formed Razgriz Squadron intercepted and shot down the Arkbird, which crashed and exploded in the Ceres; it is unknown if any wreckage of the Arkbird survived the detonation of the nuclear warhead on board.
On December 29, the Kestrel and its fleet were spotted by a large fleet of Yuktobanian Navy warships in the northern Ceres Ocean. Despite Yuktobanian Prime Minister Nikanor's address to his countrymen, the Yuktobanian fleet commander disregarded Nikanor as a traitor and ordered the sinking of a vessel that refused to attack the Oseans. Three more Yuktobanian warships consequently defected from their fleet and joined with the Kestrel. A large battle soon broke out between the two navies as the Razgriz protected the defecting Yuktobanian vessels. Suddenly, a large Osean naval fleet entered the area and opened fire on the Kestrel's fleet, believing it to be in league with the enemy; the Razgriz consequently sunk the Osean vessels as well.
The next day, the Kestrel was struck by two Yuktobanian submarine-launched cruise missiles on its port side and began to list. However, the Razgriz fighters successfully launched before the carrier finally sank into the Ceres. The Kestrel and the Yuktobanian submarine that sank it are the last known vessels to be sunk in the Ceres Ocean during the war.
- Front Line, Ace Combat 5: The Unsung War.
- Cutscene 24, Ace Combat 5: The Unsung War.
- Strangereal Map. Retrieved August 6, 2016.
- Shorebirds, Ace Combat 5: The Unsung War.
- Open War, Ace Combat 5: The Unsung War.
- Narrow Margin, Ace Combat 5: The Unsung War.
- First Flight, Ace Combat 5: The Unsung War.
- Rendezvous, Ace Combat 5: The Unsung War.
- Lit Fuse, Ace Combat 5: The Unsung War.
- Final Option, Ace Combat 5: The Unsung War.
- White Bird (Part II), Ace Combat 5: The Unsung War.
- Sea of Chaos, Ace Combat 5: The Unsung War.
- Cutscene 25, Ace Combat 5: The Unsung War.