Calling "all hands" at 04:00 to complete preparations for action, the ships went to general quarters an hour later. "Iowa" began the action at 05:16 with her forward 6-pounders. For two and a half hours, the ships bombarded the Spanish positions at San Juan. "Amphitrite" hurled 17 10-inch (254-mm) shells shoreward, as well as 30 4-inch (102-mm) shells, 30 3-pounders, and 22 6-pounders in the course of the action. The blast from the ship's 10-inch (254-mm) guns destroyed the gig and railings on the superstructure, and other items of minor damage which did not "destroy in any degree the efficiency of the vessel". The chronic irritation of the ship- poor ventilation -afflicted the ship in the course of the action, when a gunner's mate on duty in the after turret died from the heat. "Amphitrite"s Capt. Barclay commented on the lamentable conditions in his after-action report, pointing out that when the ship was closed up at action stations, the "utter lack of ventilation below ..." produced "heat so intense as to render it almost impossible for men stationed there to remain at their posts."