A Black Fleet is one of the fleets that make up the Obsidian Navy. There are fifteen such Black Fleet in the navy, and they account for the majority of the navy's major warships and naval personnel. A single Black Fleet is regarded as the total sum of warships needed to enforce Xai control over a single sector, after-which the fleet is named. A single fleet contained a total of 5,153 warships and another 1,242 support ships, and 2,323,928 naval personnel. These fleets could be divided into smaller portions for missions or patrols according to the need and size of their operation, but always have the same number of ships and personnel.