Aviso

A French aviso colonial of the Bougainville class

An aviso (formerly also an adviso), a kind of dispatch boat or advice boat, survives particularly in the French navy, they are considered equivalent to the modern sloop.

The Dictionnaire de la Marine Française 1788 – 1792 (by Nicolas-Charles Romme) describes avisos as "small boats designed to carry orders or advices".

French World War I avisos, used also during World War II, had displacement 300-700 tons, speed 13-20 knots, main armament usually of two 100 mm guns, two 138 mm guns or four 100 mm guns. In English nomenclature they are often referred to as sloops. Colonial avisos, such as the Bougainville class, intended for overseas service, were larger.

The Portuguese Navy also built avisos to operate in the Portuguese Colonial Empire. The Portuguese built 1st Rate avisos (Afonso de Albuquerque class) of 2400 tons and 2nd Rate avisos (Gonçalo Velho and Pedro Nunes classes) of 1200-1700 tons. In 1932, the Portuguese Flower class sloops were also classified as 2nd Rate avisos.

Modern avisos have grown to become combat-capable ships, smaller in size than a corvette, but larger than patrol ships. They typically have roles in anti-submarine warfare and coastal defence. In NATO classification they are usually recognized as corvettes.

See also

• Flores class sloops - Dutch colonial avisos officially rated as "Kanonneerboot" (gunboats)
• HNLMS Johan Maurits van Nassau - improved Flores class sloop
• USS Erie (PG-50) and USS Charleston (PG-51) - US Navy gunboats similar to colonial avisos
• D'Estienne d'Orves class - modern French avisos