By the end of January 1866, Commander Mendez Nuñez, after being informed about the position of the enemy squadron, ordered the heavy frigates Villa de Madrid, under Captain Claudio Alvar Gonzalez and the Reina Blanca, under Commander Juan Topete, to lift the blockade on Valparaiso and sail towards Abtao. The idea was to intercept, destroy or cause severe damage to allied warships.
On February the 4th, the twin 1,600-ton corvettes America and Union under Lieutenants Benjamin Mariategui and Miguel Grau, respectively, joined the Chilean-Peruvian naval force at Abtao, without the Spaniards knowing about these reinforcements. (The America would be lost in a tidal wave in 1874 while the Union would serve in the 1879 naval campaign).
On the early morning of February the 7th, 1866, the Villa de Madrid and the Blanca finally appeared off the inlet of Abtao but their commanders were afraid to risk their ships in shallow water and they remained at the entrance. At 10:00 A.M., the Covadonga, which was patrolling the area, noticed the presence of the enemy ships. The Commander of the Peruvian First Naval Division, old Captain Manuel Villar, who had assumed command of the allied force (The Apurimac, America, Union and the Covadonga) ordered a battle line to be formed in order to control the only two entrances to the facility. At 15:00 hours the Spaniards decided to advance trough the widest channel, first the Reina Blanca, followed by the Villa de Madrid.
Thirty minutes later, when the Spaniards were about one mile close to the allied positions, Commander Villar ordered the 1,660-ton frigate Apurimac to open fire. The rest of the fleet followed. The Spaniards answered and an artillery duel erupted between the Spanish combined 96 guns against the allies 57. Some Spanish projectiles reached the flotation line of the Apurimac, forcing her to move to the north. Another Spanish grenade hit the Union, and killed two of her crew. The America was also hit. The fight continued but with little effect. The Spanish gunnery was ineffective, while the allied ships, in spite of being at anchor, without steam, and some of them even with their engines under overhaul, fought with great energy and determination. The Chilean Covadonga, under Lieutenant Manuel Thomson, managed to fire over an island and scored several hits on the Blanca, at a distance of only 600 meters.
After two hours, in which about 1,500 shots were exchanged, the Spanish ships, which had suffered some casualties and damage, started to withdraw protected by their fire. Both sides incurred damages, but at the end the Spaniards suffered the worst. The Reina Blanca’s waterline, near the screw, was almost destroyed. She had been hit sixteen times, while the Villa de Madrid received eleven impacts. Afraid of the shallow waters and realizing that a long-range gunfight could affect their ships further, the Spanish commanders retreated to Valparaiso. The battle ended indecisively without more developments. Although it had not been a decisive contest, the allies considered it a great morale-boosting victory. In their first combat exam against a European power, the South Americans had performed brilliantly, had showed great determination and had given a lesson of courage. The Spaniards on the other side, understood that their enemies had a retaliation capacity that could put in risk their military adventure. In his report to Mendez Nuñez, the Spanish Commander Claudio Alvar Gonzales wrote:
“The most accurate and effective gunfire came from the Peruvian corvettes Union and America”
Commander Mendez Nuñez, like his predecessor, failed in his efforts to conquer the allies. The Spanish could not attack the land forces and now they had been frustrated in engaging the allied squadron at open sea. The Spanish ships were isolated, short of supplies, and without any hope of victory. The arrogant aggressors had turned into desperate men who needed a spectacular feat to save their honor. In Spain, the government and the newspapers continue demanding revenge. The result of Abtao was incompressible for those who thought that the South Americans were incapable people that would panic with the sole presence of the most insignificant Spanish warship.
Upon being informed of this setback, Mendez Nuñez, in a state of rage, proceeded south, this time with the powerful Numancia and the Reina Blanca, to search for the allied squadron and force a new combat. After Abtao the allies had moved their fleet to another Chilean naval facility at Huito, which was better protected. Mendez Nuñez was not able to attack such position without risking his ships and had to abort his plans.
On March 25, the Peruvian corvettes Union and America, sailed towards the straight of Magellan to intercept a new Spanish warship, the frigate Almansa, that according to intelligence sources was sent by Madrid to reinforce its Pacific squadron. The Peruvians remained in the area for almost a month but could not find her. The Almansa would only arrive on South American waters during the last week of April.
After this, the allied fleet remained in the Southern Chilean waters waiting for the arrival of the Ironclads, a factor that surely would change the balance of forces.
