A leaning fence on this coast almost never failed at the panels. It failed at the posts, and it failed because somebody set them the way you'd set them in Georgia clay.
Sand doesn't grip
Clay soil locks around a post and holds it. Sand flows. It gives a post far less lateral grip, and every wind event works the post back and forth in its hole, opening a gap that lets water in and loosens it further. Add a tropical-season blow pushing on a solid privacy fence — which acts like a sail — and shallow posts start their slow lean.
How deep is deep enough?
The inland habit is a shallow hole and a bag of concrete. In sandy soil, the working rule is that more of the post belongs underground than most installers put there — depth sized to the fence height, the wind load of the panel style, and the specific soil on your lot. A solid privacy panel needs more anchoring than an open picket that wind passes through. Gate posts need the most of all, because they carry swinging weight forever.
Concrete matters too: properly sized, poured to shed water away from the post rather than cupping it.
What we do differently
Before we dig, we walk the line with you, check the soil, and set depth accordingly — deeper than the code minimum where the lot calls for it. It costs us more time per hole. It's also why the fence is still plumb when the next storm season has come and gone.
Weighing materials? Read our wood vs vinyl vs aluminum comparison, check what corrodes first in salt air, or see the full fencing service.