(no place is completely safe) that I know of:
1. Osprey Marina, Mile 373.2, off the Waccamaw River, SC.
2. Skull Creek or Windmill Harbor at Hilton Head
, Miles 555 or so, SC.
You probably don't want to go much further south than that, I am gathering. Keep in mind that the whole Cape Hatteras area is a hurricane
magnet, so that anything from Beaufort
, NC, to Norfolk, VA, is likely to get hit by a storm or two or more. I'd prefer to leave my boat in the Chesapeake and then move it south if you have to leave it for a few months during hurricane season.