The only place I can gain access to the beach at Kiawah is at the county park at the south end of the island.
I have tried walking for a couple hours up the beach and detecting back and found very little.
I hit the south end of the island a couple times each year in Nov and usually dig up some clad I have found a couple 14k rings down there but my trip early in Nov only wielded some clad in one small area Lots of flat beach with deep sand so targets can be difficult to find
Vacationed there a few times, beautiful island! Never detected there so I can't comment on that. But make sure you have breakfast at the Jasmine Porch
Have fun!
I have heard one guy in our metal detecting club CLAIM that he dug a lot of clad on Kiawah. But he claims large dollars in finds on every beach he detects. I Suspect that the prospects are better further up the beach from where I detect. But in the past 4 years I have found two 14k rings down there and I usually only hit that end of the island a couple of times a year but it is not an easy place to detect.