Ark number 4 was one of nine planned arks to be built and designed to carry a large amount of humanity, animals, and whatever is needed to be kept alive during the global catastrophe. This large, heavy vessel was intentionally built for the American contingent, commandeered by Captain Michaels himself
During the evacuation, Ark 3 was permanently shut down due to slow repairs in its roof during the shifting of Earth's plates. Although the American flagship had the American flag on it, there were Chinese, Nepali, American and even Russians that have been left behind, instigating a riot to board the ark as soon as the ark was rolled out of the open blast shield doors.
Upon the impact of the tidal wave,Air Force One was caught in the tidal wave and slammed into the hull, knocking off the starboard anchor. The long amount of time used up by the delay caused seawater to flow in, causing a flood in the aft parts of the ship. Even in the mechanisms, the gears (which have been caused by Jackson and his group, even Gordon's death) have disabled the systems for a while, leaving the Ark helplessly turning to the right and grinding with the ark carrying the European/ Asian contingents.
The failed startup of the engines knocked the vessel off course, leading to it helplessly floating towards Mount Everest.
Before the hulk of floating metal could bury itself into the slope and oncoming avalanche, the engines were successfully started, backing the ark up, and was able to sail away from the flooded Himalayas.
27 days into the voyage, Ark 4 was able to re-establish contact with their foreign contingents and head to the Cape of Good Hope, and the re-emerged Africa, to rebuild humanity anew.