Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.
And here is a 2002 article by the Mel fisher Heritage Museum talking about and showing a variety of x-rayed concretions.
And here is an article about Frank Garcia digging up Florida fossils.
Beach conditions are currently poor for finding cobs. The photo below shows a typical beach. Not much but sand.
We'll have a few more days of decreasing seas before another front comes through and the waves pick up again.