BDA, I clipped this together from some links I have. Remember that it is your responsibility to know the law, especially on the lease beaches. According to the law If you found a cob or escudo in the water, and did not have a valid lease with the state, it would be Florida property.
The good news is that high tide to low tide is finders, keepers. HH.
There are no Florida laws or state statutes that prohibit you from diving with a metal detector. It is true however, that you must stay out of leased sites (see below), and out of some protected habitats with your detector. Additionally, you must abide by Florida law should you find anything on the bottom and recover it. Don't; effective 1 June 2005, the state of Florida did away with the Isolated Finds program. This program gave treasure hunters the opportunity to keep the find as long as they provided the state with the location.
It is now against the law to recover anything in state waters more than 50 years old. As a diver you are responsible for knowing these laws and locations before you dive with your detector. In Florida state waters include all submerged bottom lands to include lakes, rivers and three miles out into the ocean on the East coast, nine miles out on the Gulf Coast, and twelve miles out from Key West.
(can't post the link)
Sovereign submerged lands are those natural or
historically submerged lands owned by the State
of Florida, either by right of statehood or by deed
or grants. They include tidal lands, islands, sandbars,
shallow banks, and lands waterward of the
ordinary or mean high water line, beneath navigable
fresh water or tidally influenced water.
http://www.mcatoolkit.org/pdf/Publications_and_Presentations/Pub_FL_Sumberged_Lands_Primer.pdf
http://www.leg.state.fl.us/statutes/index.cfm?App_mode=Display_Statute&URL=Ch0267/titl0267.htm&StatuteYear=2007&Title=%2D%3E2007%2D%3EChapter%20267
Any person who by means of excavation either conducts archaeological field investigations on, or removes or attempts to remove, or defaces, destroys, or otherwise alters any archaeological site or specimen located upon, any land owned or controlled by the state or within the boundaries of a designated state archaeological landmark or landmark zone, except in the course of activities pursued under the authority of a permit or under procedures relating to accredited institutions granted by the division, commits a felony of the third degree, punishable as provided in s. 775.082, s. 775.083, or s. 775.084, and any vehicle or equipment of any person used in connection with the violation is subject to forfeiture to the state if it is determined by any court of law that the vehicle or equipment was involved in the violation. Such person shall forfeit to the state all specimens, objects, and materials collected or excavated, together with all photographs and records relating to such material. The court may also order the defendant to make restitution to the state for the archaeological or commercial value and cost of restoration and repair as defined in subsection (4).
http://www.leg.state.fl.us/statutes/index.cfm?App_mode=Display_Statute&Search_String=&URL=Ch0267/SEC13.HTM&Title=->2007->Ch0267->Section%2013#0267.13
