At 3 o'clock in the morning all hands were called on the Iowa, a few final touches in clearing ship were made, and at 5 "general quarters" sounded. The men were eager for the fight.
The tug Wampatuck went ahead and anchored its small boat to the westward, showing ten fathoms, but there was not a sign of life from the fort, which stood boldly against the sky on the eastern hills hiding the town.
The Detroit steamed far to the eastward, opposite Valtern. The Iowa headed straight for the shore. Suddenly its helm flew over, bringing the starboard battery to bear on the fortifications.
At 5:16 a.m. the Iowa's forward twelve-inch guns thundered out at the sleeping hills, and for fourteen minutes they poured starboard broadsides on the coast. Meanwhile the Indiana, the New York, and other ships repeated the dose from the rear. The Iowa turned and came back to the Wampatuck's boat and again led the column, the forts replying fiercely, concentrating on the Detroit, which was about 700 yards away, all the batteries on the eastward arm of the harbor. Thrice the column passed from the entrance of the harbor to the extreme eastward battery.
Utter indifference was shown for the enemy's fire. The wounded were quickly attended, the blood was washed away, and everything proceeded like target practice.
Morro battery, on the eastward arm of the harbor, was the principal point of attack. Rear Admiral Sampson and Captain Evans were on the lower bridge of the Iowa and had a narrow escape from flying splinters, which injured three men. The Iowa was hit eight times, but the shells made no impression on its armor. The weather was fine, but the heavy swells made accurate aim difficult.
The broadsides from the Iowa and Indiana rumbled in the hills ashore for five minutes after they were delivered. Clouds of dust showed where the shells struck, but the smoke hung over everything. The shells screeching overhead and dropping around showed that the Spaniards still stuck to their guns.
The enemy's firing was heavy, but wild, and the Iowa and New York were the only ships hit. They went right up under the guns in column, delivering broadsides, and then returned. The after-turret of the Amphitrite got out of order temporarily during the engagement, but it banged away with its forward guns. After the first passage before the forts, the Detroit and the Montgomery retired, their guns being too small to do much damage. The Porter and Wampatuck also stayed out of range. The smoke hung over everything, spoiling the aim of the gunners and making it impossible to tell where our shots struck. The officers and men of all the ships behaved with coolness and bravery. The shots flew thick and fast over all our ships.
The men of the Iowa who were hurt during the action were injured by splinters thrown by an eight-inch shell, which came through a boat into the superstructure, and scattered fragments in all directions. The shot's course was finally ended on an iron plate an inch thick.
At 7:45 a. m. Admiral Sampson signaled "Cease firing." "Retire" was sounded on the Iowa, and it headed from the shore.