A flotilla, or naval flotilla, is a formation of small warships that may be part of a larger fleet. A flotilla is usually composed of a homogeneous group of the same class of warship, such as frigates, destroyers, torpedo boats, submarines, gunboats, or minesweepers. Groups of larger warships are usually called squadrons, but similar units of non-capital ships may be called squadrons in some instances, and flotillas in others. Formations including more than one capital ship, e.g. men-of-war, battleships, and aircraft carriers, typically alongside smaller ships and support craft, are typically called fleets, each portion led by a capital ship being a squadron or task force. A flotilla is usually commanded by a rear admiral, a commodore or a captain, depending on the importance of the command. A flotilla is often divided into two or more divisions, each of which might be commanded by the most senior commander, nearly always a lieutenant at the very least. A flotilla is often, but not necessarily, a permanent formation. In modern navies, flotillas have tended to become administrative units containing several squadrons. As warships have grown larger, the term squadron has gradually replaced the term flotilla for formations of destroyers, frigates and submarines in many navies. A naval flotilla has no direct equivalent on land, but is, perhaps, the rough equivalent in tactical value of a brigade or regiment.
In the United States Coast Guard Auxiliary, a Flotilla is the basic organizational unit and consists of members at a local level where the majority of the work of the Auxiliary is done. A Flotilla is led by an elected Flotilla Commander assisted by an elected Vice Flotilla Commander, who is in turn assisted by appointed Flotilla Staff Officers. A Coast Guard Auxiliary Division consists of multiple Flotillas and a District consists of multiple Divisions. Auxiliary Districts are organized along Coast Guard District lines and are administered by a Coast Guard officer who is called the Director of the Auxiliary.
The word flotilla has also been used at times to refer to a small fleet of vessels, commercial or otherwise. There is also such thing as a flotilla holiday, in which is a group of chartered yachts that set sail together on the same route.
