ANYTHING that is on or near water requires permitting and even more being in the Chesapeake Bay Watershed (https://www.chesapeakebay.net/discover/watershed) It's the Communist Wealth I rebuilt a deck( well actually paid a contractor for that one) at our last home and had to have it permitted as they said I was changing the offset. The damn thing went in the SAME EXACT spot with one exception. Code said it had to be attached to my house and not free standing which equated to 2"....the width of the 2X10 they used for the header. Probably dimensionally it physically changed less than that. Here see if you can spot the difference requiring a permit It's ALL about the money.