Esmeraldas-class

The Esmeraldas class is a group of six corvettes built in Italy for the Ecuadorian Navy, ordered from Cantieri Navali Riuniti (CNR, later part of Fincantieri) in 1978–1979 and entering service in the early 1980s. The design is CNR's Type 550 export corvette, related to the Assad and Laksamana classes, and was derived directly from the Wadi M'ragh missile corvettes delivered to Libya in the late 1970s. Compared with the Libyan boats, the Ecuadorian ships received more powerful machinery for higher speed, together with revised armament and equipment.

Propulsion is by four MTU MA20 V 956 TB 92 diesels driving four shafts. Anti-ship armament consists of six Exocet MM40 missiles in two triple mountings amidships, with a range of 70 km. Air defence is provided by a quadruple Albatros launcher firing the Aspide missile out to 13 km, sited at the after end of the superstructure behind the mast; no reload rounds are embarked. An OTO Melara 76 mm Compact gun is mounted forward and a twin Bofors 40 mm mounting aft. Two triple 324 mm tubes for Italian Whitehead A244 anti-submarine torpedoes were fitted as built. A helicopter landing platform lies between the Exocet launchers and the Bofors mounting and can take a Bell 206, though the corvettes have no hangar.

The sensor fit comprises a Selenia RAN-10S air/surface search radar, two Selenia Orion 10X fire control radars and a Thomson Sintra Diodon hull-mounted sonar.

El Oro was badly damaged by fire on 14 April 1985 and was under repair for two years. In 1991 the torpedo tubes were removed from two of the corvettes for transfer to the two Leander-class frigates bought from the British Royal Navy, BAE Presidente Eloy Alfaro and BAE Morán Valverde. An upgrade of the combat and fire control systems planned for 1993–1994 was not carried out for lack of funding.

Three ships of the class — Los Ríos, Manabí and Loja — were refitted for life extension by Astinave and re-delivered in 2017–2018. The work included installation of a locally developed combat management system designated Orion.