"Otago" and were the only two "Otago"-class frigates; they differ from the "Rothesay"s that served in the Royal Navy as they were not reconstructed to the Type 12I "Leander"-class standard with hangar and landing pad for a Westland Wasp anti-submarine helicopter as the main weapon system with torpedoes, depth charges and SS.12/AS.12 missiles to engage fast attack craft and surfaced submarines.