Shuffling the blockaders
Commander Marchand, senior officer off Charleston, spent the day moving ships: the Bienville to Rattlesnake Shoal, the Unadilla off Stono instead of coaling, the Keystone State back to Port Royal, one steamer doing the work of two. The blockade of Charleston was a permanent shortage of hulls, coal and boiler tubes.
Official Records of the Navies, Series I, Vol. 13