It was my understanding that signs can only prohibit from carrying inside a building, not on grounds. Correct me if I'm wrong. From Myrtle, but haven't been to Ocean Lakes since I began carrying so I never paid attention.
Oh and if you are leasing a plot for a camper you hold the leased fee interest. Which basically is a legal contract. Now, if you get made the cops may still give you a hard time and you may be asked to leave by Ocean Lakes, but in court I don't know if they would have any grounds.