 The harbor was well defended, with five Confederate harbor forts each capable of destroying the boat. But Smalls knew all the proper signals and even impersonated the captain standing at the front of the boat. Once free of the harbor, they lowered the Confederate flag and put up a white sheet, hoping the ships of the Union blockade would see it. Yet they were still nearly fired upon by the Federal blockade fleet, as the captain of the armed clipper USS Onward, seeing the Confederate gunboat, ordered the guns to ready.