four o'clock
The Confederate mosquito fleet , consisting of the little gunboats _ Patrick Henry _ , _ Teaser _ and _ Jamestown _ , swung down from the river now , ran boldly past the flaming shore batteries and joined in the attack on the Federal squadron . The _ Congress _ had set one of her sails and with the aid of a tug was desperately working to reach shoal water before she could be sunk . Her captain succeeded in beaching her directly under the guns of the shore batteries . At four o'clock she gave up the bloody unequal contest and hauled down her colors . The _ Minnesota _ , _ Roanoke _ and _ St. Lawrence _ , in trying to reach the scene of the battle , had all been grounded . The _ Minnesota _ was still lying helpless in the mud as the sun set and the new monarch of the seas slowly withdrew to Sewell 's Point to overhaul her machinery and prepare to finish her work next day . The _ Merrimac _ had lost twenty-one killed and wounded -- among the wounded was her gallant flag officer , Franklin Buchanan .