If you go on the link you posted it says specifically "use of metal detectors in all national parks prohibited". There is a public beach access right there at whalebone junction and if you walk out there on the beach you will see a line of steel stakes that is the whole width of the beach from the dune to the water designating the line for the national seashore. North Carolina park services has gotten really crazy about the national seashore and three weeks ago when I was down there, if you were on the national seashore and walking on the beach, you had to stay a certain distance within the shoreline. You could not just walk all over the beach and no, I'm not talking about walking on the dunes...I know you can't do that. The locals told us it has to do with some migratory bird and if even one bird is spotted in the area they will even go as far as to close down that area of the beach totally. So if you go below those stakes at whalebone junction with a detector your taking your chances.