Yep. It’s against the law for anybody to metal detect in the Florida dunes. The penalties can be severe.
Second, it’s against the law for YOU to be in the dunes. You got off easy.
Third of all, do you realize what a challenge you threw out for anybody willing to help you? How long do the dunes run? How deep are they side to side? Imagine the effort it would require going up and down that soft sand.
Yesterday I was asked to look for a lost gold cross. The owner lost it while on a 9 mile jog. The momentum that cross would have had could easily cover up to a 50’ range. Multiply that by 9 miles and it would take 3+ days to cover the area.
Sorry but I have other things to do.