PB,
I can only speak for SC and Georgia... ingress is limited through here, and it takes a long time to get in and out. A friend of mine who cruises between HHI and Lake Worth makes a point of getting outside and staying outside for 2-3 days at a pop when he wants to make time. From my home port on HHI, it takes me approx. 4 hours to get out far enough to turn left or right for safe passage. I'm going to be making my first overnight sail to Charleston in a month, and that's what I planning on. By the way, Cam sent me a link to this book. You might find it helpful...
http://www.whitesoundpress.com/detail%20seinlet.htm
Stop in and say hello when you get to HHI, especially if you come in via Port Royal Sound. You can borrow the family car to re-pro if needed.
Best,
Sailhog