Hey Bro- I got the watch and just looked. I don't know where Folly beach is, but they have myrtle beach sc, and a couple in nc- like wrightville. so check out what the time difference is between myrtle beach and folly. It its only a few minutes, its not going to make a difference. with this particular watch you can actually adjust any of the presets- or customize it so that its correct for your spot.
I would get the watch. I got it and love it. best one I ever had. plus the tide diagram is super accurate- like how low the tide is going and how long its going to stay low before the push starts for incoming.
Amazon bro- its like 60 bucks. i wear mine all the time. best watch all around. get it.