Around that time, Prat faced an unusual situation. On May 24, 1875, "Esmeralda" was in the port of Valparaíso while Prat was on sick leave. The commander of the ship, Luis Alfredo Lynch, was also on leave so Lieutenant Constantino Bannen was left in charge. A storm began in the bay and "Valdivia" broke its ties and went right towards "Esmeralda", which then impacted with "Maipo". It appeared that the destruction of "Esmeralda" would be unavoidable. When Prat and Lynch returned, they managed to get transported back to the ship by boat, but the violent waves kept them from embarking. Arturo Prat threw himself into the water and swam to the ship to climb a rope (as Lynch had done just before him). He worked feverishly with a rope tied from his waist to the mast to accomplish rescue maneuvers resulting in the ship stopping with its bow against the beach and securing it there with rigging. Luis Alfredo Lynch would later remember Prat's "unflappable calm in the face of danger".