Very nice photos! I like the one of the lightship.
Not sure about other places, but along the NC OBX, light ships were used in place of, or to supplement, light houses, to warn mariners of dangerous offshore shoals. There were 3, Frying Pan Shoals, (later replaced with an offshore light tower, which was finally de-commissioned) Cape Lookout, and Diamond Shoals.
Just a little of the history that's part of the US Lifesaving Service and the US Lighthouse Service.
Here's the story on that particular ship:
https://www.uscg.mil/history/WEBORALHISTORY/lv116chesapeakeoralhistory.pdf