On March 25, the Peruvian corvettes Unión and América were sent to the Strait of Magellan to intercept the Spanish frigate Almansa, that according to intelligence reports, had been dispatched from Spain to reinforce the Pacific fleet.
The rest of the Allied fleet remained on the defensive in southern Chile, awaiting the arrival of the ironclads Huáscar and Independencia, destined to become the factor that would change the force equilibrium.