With its completion in 2039, it was said that Neucom could "make the impossible possible". Megafloat is the first and only sea-faring city ever made in the planet's history. Neucom Inc. placed a small air base on Megafloat and also used the city as a supply point and staging area for their naval and air forces. From the beginning, this city was built along with many private plant and research facilities. However, at later time, it was essentially functioning as military base. Private residences were also built and sold only for employees of the facilities.
In 2040, during the Intercorporate War, Neucom Inc. sent multiple Military Naval Vessels to Megafloat, using the city as a staging point for attacks on General Resource LTD. The Universal Peace Enforcement Organization's Special Armed Response Force (SARF) along with aces from the General Resource Defense Force engaged Neucom's vessels before they could dock at Megafloat. This unified attack sparked tensions between Neucom Inc. and the UPEO, with Neucom proclaiming the UPEO as nothing more than "General Resource's puppet".
The Ouroboros launch a full-scale attack against Megafloat. Supported by the UI-4053 Sphyrna, multiple aircraft and a small naval fleet with an aircraft carrier bombard the city. Betrayed by Abyssal Dission, former Neucom Emergency Unit Ace pilots Cynthia Bridgitte Fitzgerald and Nemo, once a part of the Ouroboros, leave the organization and intercept the entire force at Megafloat. Despite their success, the X-49 Night Raven destroyed Megafloat with only one Heavy Laser Cannon shot. The laser cannon impact ripped a hole into the middle of the city and caused a large tsunami to form, ripping the city to pieces. Before the UI-4053 Sphynra could leave the area, Cynthia and Nemo engaged the Sphynra and its escorts, resulting in the destruction of the airship and the escape of the UI-4054 and X-49 in the nearby Geofront.
In another scenario, after the destruction of Megafloat, a number of XR-900 Geopelia airframes were launched from the city's remains to attack the nearby city of Port Edwards. Nemo, who was with General Resource at that time, took care of the threat shortly after.
Megafloat in the real world
Megafloat could be based on the real life idea of a floating airport. The Japanese Ministry of Land, Infrastructure, and Transport sponsored the construction of Mega-Float, a 1000-metre floating runway in Tokyo Bay.
The Mega-Float was a research testbed built in two years (1998-1999) with the purpose of evaluating whether the concept of a floating airport was feasible or not. Its research also included the environmental impact of the Mega-Float on its surrounding eco-systems.
After conducting several real aircraft landings, the Ministry concluded that floating runways' hydro-elastic response would not affect aircraft operations, including precision instrument approaches in a protected waterway such as a large bay. The structure has been dismantled and is no longer in use.
- Megafloat can be seen under construction in one of the challenge missions in Ace Combat 04: Shattered Skies.
- The L.A. and New York Megafloats from the Combat Simulation Games Lethal Skies II and LS:EP Team SW follow a similar design method to Neucom's Megafloat.
- Neucom did not exist when Megafloat began construction, as indicated by the Erusean Air and Space Administration, which eventually became Neucom, being around in Ace Combat 7: Skies Unknown, over a decade after Megafloat was seen in Ace Combat 04. It is unknown who initially began construction on Megafloat.