The Piratini Class is a class patrol vessels (NPA) of the Brazilian Navy built the Rio de Janeiro Navy Arsenal, Cape-based class of North American origin. These ships were built between 1970 and 1971 and classified as Coastal Patrol Vessels (NAPAC). The machine gun and mortar twinned bow was replaced in 1985 by a 20mm cannon Oerlikon Mk 10. In 1993 they were transferred to patrol the rivers defended by the Mato Grosso Fleet acting also in the North Naval Group, for his project ever considered use in rivers.