Viana do Castelo-class

The Viana do Castelo class is a series of offshore patrol vessels developed for the Portuguese Navy under the NPO2000 (Navios de Patrulha Oceânica) project. The class was designed to replace the João Coutinho and Baptista de Andrade-class corvettes and the Cacine-class patrol boats. Construction originated at Estaleiros Navais de Viana do Castelo (ENVC) and transitioned to West Sea Shipyard. The Portuguese government has authorized a total of ten vessels, with the first unit commissioned in March 2011.

The class consists of two primary configurations: the Ocean Patrol Vessel (NPO) and the Navios de Combate à Poluição (NCP), an anti-pollution variant. The NCP version is equipped with systems for the recovery and transfer of oceanic pollutants, including fast oil recovery systems, barrier launchers, and floating tanks. These vessels utilize internal vapor circulation coils to heat pollutants and facilitate extraction. Standard design features for the class include automated systems, water cannons, and rigid inflatable boats. The vessels are equipped with a medium-sized helicopter pad capable of supporting Super Lynx Mk.95 operations, though they lack a hangar.

The onboard sensor suite includes the Leonardo Medusa MK4/B electro-optical fire control system, SAGEM surveillance platforms, inertial navigation systems, and multiple navigation radars. Armament across the class includes turreted guns, machine guns, and mine-launching systems. The third series of vessels is planned to incorporate torpedo tubes, countermeasure launchers, and Protector remote weapon stations. Modernization efforts during maintenance cycles are intended to integrate modular systems for anti-submarine warfare and vertical take-off and landing unmanned aerial vehicle operations.

The Portuguese Navy employs the class for fisheries protection (SIFICAP) and search and rescue (SAR) missions in the North Atlantic. Four vessels are currently in active service. NRP Viana do Castelo and NRP Figueira da Foz comprise the first series, with the latter assigned to operations in the Azores and Madeira. The second series includes NRP Sines and NRP Setúbal, commissioned in 2018 and 2019. Six additional vessels are currently ordered or approved, with the fifth vessel of the class, NRP Porto, under construction.