Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.
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Fort Pierce Inlet.
Snipped from Floridadep.gov. Full link below.
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I mentioned a project to find gold bars dropped along a West Coast beach a few decades ago. The bars were scattered to some extent. Those hunting the bars have a general description of where the bars were dropped (scattered) relative to the beach and a delta.
Since the bars were dropped a few decades ago, the first thing I'd want to know is where the shoreline was when the bars were dropped relative to where the shoreline is now. Beaches change over time and it is important to know where the beach was relative to where it is now. That is often an overlooked and very important piece of information.
Let's just say the bars were said to be dropped along the shoreline very close to the water. Where was the water line at that time? Was it farther out than it is now, or is it now under the beach.
If we use the Fort Pierce inlet area as an example, we know that north of the inlet the sand has been accumulating for quite some time, and the shoreline just south of the inlet continually erodes. The shoreline to the north of the inlet has been moving one way, while the shoreline south of the inlet has been moving the other. If the bars were dropped along the waterline, if they were dropped north of the inlet a few decades ago, they would probably be under the beach now.
Fortunately there is good detailed data on shoreline changes. For Florida you can find very detailed data for most of the 20th and 21st century. If you do the research you can find out where the beach was back some years ago and compare that with where the beach is now.
If you were told that a bar was buried ten yards back from the water line fifty yards south of the Fort Pierce inlet fifty years ago, it might seem like you'd have a good idea of where that bar was. However, the shoreline might have changed a lot in those fifty years. In recent years the beach just south of the inlet changes a hundred yards east/west every year or two when they renourish the beach and then it erodes again. You can't just go out to the waterline and march back fifty yards and figure that is where the bar is.
It doesn't have to be bars of gold. Resort beaches have changed the same way. One beach that I hunted a lot in the past is now covered by at least a hundred yards of new sand. The beach and dips in front of that beach that I worked thirty years ago are now deeply buried, as are the items dropped there back then. It helps a lot to know where the beach was compared to where it is now.
Below is an example of a map that shows how erosion changed a shoreline between 1954 to some time in the 2000s. If there was a swimming beach at this location in the 1950s hundreds of yards farther out than they would be most recently. Or if there was a shipwreck offshore, it would now be much farther out from shore.
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| Map Showing How a Shoreline Changed Over a Few Decades. |
There will be daily, monthly, yearly changes, but there are also fluctuations that occur over decades and centuries. A shipwreck that was in the water could now be under the beach if it is in an area where there is accretion rather than erosion.
Florida provides an immense amount of shoreline data. The database is not easy to use unless you are familiar with it, but the information is there if you are willing to do the hard work.
Here is a link to the Florida shoreline database.
https://floridadep.gov/water/beaches/content/historic-shoreline-database
If you take the time to dig into it, you'll be amazed at the detail that is available. There is map, survey and photographic documentation on virtually every foot of shoreline.
If you look at the photo at the top of the post, you'll see that there are six small red triangles west of the shoreline. Those are the survey monuments.
The Florida Public Land Survey System (FLPLSS) was established by the United States Government Land Office (GLO, now re-organized under the Department of the Interior, Bureau of Land Management, BLM) beginning in 1824, with the establishment of the Initial Point in Tallahassee. This system of rectangular survey grids was gradually extended through the remainder of the 1800's eventually covering the entire state, dividing all the public lands first into six mile by six mile areas (Townships), then subdividing these Townships into one mile by one mile regions (Sections). Physical survey markers, or monuments, were placed every half mile on these section lines to delineate the surveyed lands. Monuments were also placed at points on the section lines where they intersected bodies of water or previously occupied (private) lands...
(Source: http://sfrc.ufl.edu/pdf/faculty/gibsonresearch.pdf)
I better wrap this up. If you have a general description of the location of a beach treasure, the first thing you might want to do is check to see how the beach has changed since the time of the description. It seems that people don't appreciate how much or how rapidly beaches change. You will want to know where the beach is now compared to where it was in the past.
Shipwrecks that were once underwater can now be under sand. Treasures that were once buried on the beach, can not be out in the water. People talk a lot about how items move, but beaches move too. The movement of the beach is just as or more important than the movement of the items. A lot of data is available if you are willing to dig it out.
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There is a lot more to be said on the above topic. I might pick up on it again real soon.
One reason I chose the picture at the top of the post is that it is not a simple case. It is more complex than an unbroken stretch of beach. See if you can see how the sand is flowing at various spots.
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Happy hunting,
TreasureGuide@comcast.net
