Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.
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| Fort Piere South Jetty Sand Dumping Project. Photos byJoe D. |
Joe D. sent these photo and the following report.
I read several news articles today about the new sand, and was glad to see people questioning the cost and longevity of these projects. As both a detectorist and a taxpayer, I am tired of seeing money dumped into the water for such short-lived effects. While more permanent solutions are being discussed, it remains to be seen if or when they will materialize. Seems like the same old song and dance, as we continue to pay for the same result!
Anyway, here are a few pictures of my finds from this week. Lots of juvenile spinner sharks, and some spotted rays leaping about!
Thanks again for all you do with the blog!
Best regards,
And here are Joe's finds.
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| Finds by Joe D. |
Thanks for sharing Joe. Many agree with your sentiments concerning the continual dumping of sand.
I decided to check the Manticore reading on a variety of larger targets. First, I used the four fake treasure coins I talked about in a post not too long ago.
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| Four fake Treasure Coins Used in Target ID Test. |
No. 1 (most left) is the heaviest and thickest. No. 2 and 3 are both thin and made of what I'd call pot metal. And no. 4 has more of a copper look.
I used the Manticore and for this test focused on the conductivity numbers but made a few additional observations.
No 1 produced a number that centered around 55.
No. 2 produced a number centering on 37.
No. 3 gave numbers around 32.
No. 4 gave numbers around 56.
No.s 2 and 3 are similar in weight and feel, but 2 is a touch bigger. They produced fairly similar conductivity numbers. Size has an effect on the conductivity numbers. I think I've said that before.
No.s 1 and 4 produced fairly similar numbers although they are fairly different. 1 is thicker and heavier but 4 has a slightly larger diameter and appears to be made of a different metal.
I also tested some genuine coins that I also discussed recently. They included no. 1, a morgan silver dollar, no. 2, the Eisenhower Bicentennial dollar, and no. 3, a 1943 Walking Liberty half dollar. The Morgan and half dollar are silver, but not the Eisenhower.
Here are all the coins. The fakes are on the first line and the genuine coins are on the second line.
The Morgan showed mostly 94 - 95.
The Eisenhower was ever so slightly different despite the difference in metallic composition. 94 -95.
The walking liberty produced mostly 92 - 93. That isn't much different than the Morgan despite the size difference.
In conclusion, the numbers for the fakes are pretty different from the numbers for the genuine coins.
It seems the numbers produced by the last three coins was not sufficiently different to distinguish between the three during field conditions. The numbers for both the silver and Eisenhower were not very different.
One thing that caught my attention is that as the depth increases and the signal strength decreases there is greater variance in the conductivity numbers. For deep coins with less strong signals, you get a wider range of numbers. You could probably draw a curve showing the greater variance as signal strength decreases. In my younger years I might have done that. But the main point is that you need good signal strength for to get a good narrow range of conductivity numbers.
Here is the Manticore's ID target map for the Morgan at good signal strength.
All three of these coins produced very similar high conductivity numbers with the disc shaped object on the far right of the center line.
As you pull the coil back, when you've increased the distance between the coil and target to the border line detectable distance, you'll see a big drop in the conductivity number. You'll also see the disc shaped target on the ID map become very faint. I call it a ghost signal, but the disc remains at the far right of the map. That discrepancy (between the conductivity map and the position of the object on the map) might turn out to provide useful information. It might be a good hint that your target is at near maximum detection depth. I'll investigate that more in the future to see if it holds and how useful it might be.
Below you see the display for the same target. Now it is showing 14, but the faint disc is still in about the samme position at the far right of the center line. You can't see it in this photo, but it is there
Several things affect the conductivity numbers. Of course, there is metallic composition, but there are also other things, such as the size of the target. And, now we see how the signal strength (and therefore depth or distance) can affect the conductivity number. You can't expect to get a good number without good signal strength.
Neither the differences in metallic composition or the differences in size for these particular coins made a huge difference in the target ID numbers or the target ID map.
I noted a few other interesting things but would want to replicate those more carefully before discussing them. I might do that in the near future.
You can not put too much emphasis on any one indicator, such as the conductivity number. When you get deep targets and weaker signals, you can expect the numbers to jump arouond a lot.
The ID system still seems to be most accurate and helpful when you know something about the type and likelihood of different kinds of targets and trash in the ground. You can get in trouble by overgeneralizing though.
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| 10:30 AM Sunday Fort Pierce South Zoom View. |
Check this out. It would have been easy to miss this one, a nice little cut developed last night or early this morning. That can happen with south winds, even if it doesn't typically create the kinds of monster cuts associated with big nor'easters.
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| Surf Chart from Surfguru.com. |
This morning, we have east swells and a SSE wind. The surf isn't big, but we do see some recent cuts.
Watch for the bigger surf later this week.
Good hunting,
Treasureguide@comcast.net