FL has over 1000 art. reefs. I have fished a few and there was no one one else out there on any of them, they are well marked and fishing was off the charts good. Every pass you would hook up with a different species.
My buddy was involved in deploying old subway cars off SC for a reef and also several ship sinking projects. It was an underwater desert with no fish around before the reefs were deployed. Fish show up pretty quick...and by a year they are covered with fish.