Daniel Ammen, Confederate Military History, a library of Confederate States Military History: Volume 7.2, The Atlantic Coast
Clement Anselm Evans, Ed.

[93] within effective range. The Weehawken was then somewhat above Fort Wagner. At about 3.05 she opened fire on Fort Sumter, followed by the other monitors, at or before they arrived at the same point, the Patapsco at that time employing a 150-pounder rifle, at the angle of Sumter that was in face. From Wagner up, several buoys of different colors were seen; the vessels passed between them and Morris Island, but nor far from them, perhaps within one hundred and fifty yards. It was observed that the different vessels, in bringing the buoys in range with Moultrie or batteries on that shore, received in turn a heavy fire, and it was supposed probable that they marked torpedoes; they certainly served to indicate distance, and the ranges of the guns had been practically established on them, which greatly increased the accuracy of fire from the forts as the vessels passed. As the narrow part of the channel was approached, the flood tide became strong, setting the vessels in, and made them additionally unmanageable.

Soon after getting within the heavy fire of the batteries, the Weehawken signalled obstructions in her vicinity, and previous to that a torpedo had exploded close to her; Captain Rodgers' report states: ‘We approached very close to the obstructions extending from Fort Sumter to Fort Moultrie—as near, indeed, as I could get without running upon them. They were marked by rows of casks very near together. To the eye they appeared almost to touch one another, and there was more than one line of them.’

‘The appearance was so formidable that, upon deliberate judgment, I thought it right not to entangle the vessel in obstructions which I did not think we could have passed through, and in which we should have been caught. Beyond these, piles were seen between Castle Pinckney and the middle ground.’