Flotilla

A Flotilla is the smallest Naval Unit type with three or more ships, smallest being a Task Element, Flotillas require one to hold at least the rank of Commodore.

Anti-Fighter/Bomber Flotilla
An Anti-Fighter/Bomber Flotilla generally consists of a larger warship that's guarded by Corvettes, tasked with clearing the way for it's own or the rest of the unit the flotilla belongs too own fighters and bombers to attack enemy forces.

Recon Flotilla
A Recon Flotilla generally consists of a larger warship accompanied by equal or smaller ships, all of which have good sensor coverage

Sizes of Flotillas
Like with all other Naval Units, Flotillas can vary in size depending on needs of a mission or circumstances, such as the merging of several flotillas during a battle after one has lost a flagship or significant portions of it's ships.

Halo Covenant
A Covenant Flotilla is most likely to be composed of: