A spring tide and a northeaster fill the trenches
Firing on Sumter continued. That afternoon the spring tide, driven by a northeast storm, put water from a few inches to three feet deep down nearly the whole Federal trench line; a third of the surf battery’s parapet went, and its two guns had to be taken out. That night Gillmore ordered the full sap started from the third parallel anyway.
Major Brooks’ journal, OR I, 28, Pt. 1