The eight to ten vessels of this class, specially designed to operate in the waters of the North Atlantic Ocean, will replace the João Coutinho and Baptista de Andrade-class corvettes — currently being decommissioned —, and the small patrol boats of the Cacine-class in their primary fisheries protection role (SIFICAP) and in their search and rescue (SAR) roles.

[4] The ships are designed to operate automated systems and are equipped with a single Sagem SA Vigy 10 MKIII naval surveillance and observation platform, three water cannons, and two rigid inflatable boats.

[5] The third serie of the Viana do Castelo-class will be armed with one 30 mm Oto Melara Marlin, one Mark 32 Torpedo Tube, one launching system for MK55 Mod 2 mines, countermeasure launcher, 2 x Protector RWS and various 12.7mm M2 Brownings.

[6] The Portuguese Navy is gradually upgrading its Viana do Castelo-class offshore patrol vessels (OPVs) during their maintenance cycles.

Also Viana do Castelo-class is being progressively upgraded to enable vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) operations to provide intelligence, surveillance and reconnaissance (ISR) capabilities[7]