A close-up of the southern jetty. They're less-visible at high tide.
At the mouth of the Charleston harbor is a pair of old and faithful jetties, they're a sort of sea wall that make life easier for the large cargo ships to get to and from Charleston. Thing is, inexperienced boaters often crash into these mounds of earth under the water.
Boats crash into the jetties quite often. Back in December 1997 a boat crashed on the jetties, killing four.