Not sure about down that way, but up here in Wilmington there are plenty of wrecks that are great dive spots, plenty of fish and you can get up close and personal with sharks here as well.
Most of the local fauna do not thrive well in reef tanks, maybe short term. Once these Bermuda high pressure systems move out and we get some wind from the SE there will be plenty of Macro Algae to collect such as Sargassum, Codium, Gracilleria, and Ulva. I'm not sure there are really any laws regarding the collection of inverts in the area other than commercially popular species like blue crabs and virginia oysters.
The muddy intertidal areas are a great place to collect snails and hermits, but again most aren't reef tank suitable since they are intertidal. You will find plenty of littorina snails, nassarius as well as predatory snails that will eat clams. So be sure to have a good field guide before adding to your tank