The Spanish guns were only five hundred yards away, and yet the enemy had given no sign of having seen the _Merrimac_. Then suddenly a light flashed from near the water's edge on the left side of the entrance, and a roar followed. The _Merrimac_ did not quiver. The shot must have fallen astern. Again there was a flash, and this time the crew could hear the splash of water as the projectile struck back of them. Through their night-glasses they saw a picket boat with rapid-fire guns lying close in the shadows of the shore. Her guns had probably been aimed at the _Merrimac's_ rudder; but so far they had missed their aim. With a rapid-fire gun to reply the _Merrimac_ might have demolished the other boat in half a minute, but she had no such equipment. She would have to pass within a ship's length of this picket. There was nothing to do but pay no heed to her aim at the _Merrimac's_ rudder, and steer for the high wall off Morro Castle, where the deep-water channel ran close inshore. "A touch of port helm!" was the order. "A touch of port helm, sir," came the answer; and the vessel stood toward the wall. There came a crash from the port side. "The western battery has opened on us, sir!" reported the man on the bridge to Hobson. "Very well; pay no attention to it," was the answer. The commander knew he must take the _Merrimac_ at least another ship's length forward, and wondered if the enemy would give him that much grace. A shot crossed the bridge, and struck. No one was hurt. They had almost reached the point where they were to stop. Another moment or two, and over the engine telegraph went the order, "Stop!" The engineer obeyed. The _Merrimac_ slowed off Morro rock. A high rocket shot across the channel entrance. From each side came the firing of batteries. Hobson and his men were too busy to heed them. The _Merrimac_, still swinging under her own headway, brought her bow within thirty feet of the rock before she righted. Another ship's length, and she would be at the point where her commander had planned to take her; then the stearing-gear stopped working, and she was left at the mercy of the current. The ship must be sunk before the current could carry her out of the course. This was done by exploding torpedoes on the outside of the vessel. Hobson gave the order, and the first torpedo went off, blowing out the collision bulkhead. There was no reply from the second or third torpedoes. Hobson crossed the bridge, and shouted, "Fire all torpedoes!" In the roar of the Spanish batteries his voice could hardly be heard.