I used to live in Jax, just off Roosevelt at the Orange Park line. My ex-wife had family that lived in Tanglewood, and I found some very nice coins under the big oak in the park at Kingsley and Hwy 17, once... so don't bother looking there.
But there 'aint a thing in that whole swamp-choked locale that is so pristine as to require a general ban on detecting.
I suspect this is the result of some idiot detectorist(s) getting busted tennis shoein' or tearin' up some property.
Moreover, I expect it will take hold in plenty more places, for two reasons:
1. The number of detectorists has risen dramatically in recent years, thanks to mass marketing and sales of detectors. But, frankly, many people are plain inconsiderate, and owning a detector doesn't change that - it likely exacerbates it. There are more than a few who assume they have the right to do what they want on private property, or to disregard common decency on any other property they run across. With the greed element tossed in, it is a recipe for disaster. I'm willing to bet this situation in Clay County is the result of a few bad apples which have ruined the barrel for the rest of us.
2. The word is out among John Q. Public - detectorists are pirates. They want to come on any land they deem fit, for reasons all their own, and take "valuables" without asking... and tearing up the landscape in the process. People aint stupid, these days; even non-detectorists know what our instruments are for. I've seen more news articles to that effect in recent years than I like. To many people, detectorists are looters, even the park pounder out snagging pocket change on Saturday morning.
Given the increasingly controlling nature of government and the litigious attitude of the public at large, it is only a matter of time before "somebody's needs to pass a law about them pilfering detectorists."
Of all tyrannies, a tyranny sincerely exercised for the good of its victims may be the most oppressive. It would be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end, for they do so with the sole approval of their own conscience. - C.S. Lewis
I hate to say I told you so, but once too many people get on to any one thing, someone feels the need to control it.
I'm sorry to hear of it, and I hope it passes with some good relations established all around.