[2] In March 1971, a South African project team visited Britain, France and Portugal to investigate alternative designs for future frigates or corvettes.

A decision was made to buy corvettes from Portugal, with four ships of an upgraded version of the João Coutinho class being ordered.

[3] The then Minister of Defence, P. W. Botha, had already started discussions with Israel to buy their Reshef-class missile boats, designated Project Japonica.

[3] The imposition of the international embargo on the sale of arms to South Africa on 4 November 1977 forced the project to be carried out under a cloak of security.

Three decommissioned Warrior-class strike craft were refurbished by SA Shipyards and recommissioned as offshore patrol vessels (OPVs) from 2012 to 2014.