9/15/25 Report - Treasures That Turned Out Not To Be - a Long List. Metal Detector Tests: Recommendations and a Few Observations.

Written by the Treasureguide for the exclusive use of the Treasure Beaches Report. 

I found a fun article.  It isn't totally accurate, but it does mention a number of treasures or treasure hunts. They start out with Oak Island,  

The article's title is 19 Times People Thought They Found a Lost Treasure - But Were Wrong.  The link is below.  The article does refer to a number of real treasure hunts.

The article starts out with Oak Island saying, ...their “treasures” were anything but valuable, and, Though some coins and wood fragments have been discovered, no notable treasure has ever been located. I'd also describe it as a treasure hunting Big Fail. But it isn't over yet.  Still the amount of time and money put into the search has to be rated as a big loss if you don't include the TV revenue, which has nothing to do with actual finds of value.  The Big Fail is only emphasized by the pitiful attempts to hype the story for TV consumption.  I can't image a more probed, dug, detected plot of ground with so little to show for it.

Then the article goes on to a long list of other treasure fails.  Next in line is the Beale treasure, Victoria Gold Peak, the Georgia hoax diamonds, the Spanish galleon of Maine, or the Drake plate, which turned out to be a modern fake.  Still an entertaining article even if you don't agree with how they describe or characterize things.  Many of the stories aren't exactly what you'd expect from the title such as the Oak Island one, which doesn't really fit my idea of treasure found that was actually not treasure.  

Here is that link for a fun read.

19 Times People Thought They Found a Lost Treasure—But Were Wrong

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I recently did a post on metal detector conductivity numbers and target ID.  Just yesterday I saw some advertisements praising the Manticore's new 2D ID system, so I looked into it a little and watched a few more target ID tests using the Manticore as well as some other metal detectors.  

I noticed that metal detector tests haven't improved much over the years. As a retired academic and researcher, I'm a stickler for good research design, and although I know these tests aren't scientific experiments and don't need to be they could still be easily improved.

One thing I can't get over is how virtually every test or comparison involves detectorists finding the optimal location and movement of the coil to obtain the strongest and most consistent possible signal.  You always see them repeat the sweep until they get the target perfectly centered under the coils sweet spot and find the perfect sweep speed to produce the best possible signal or reading.

In the field, it is a different situation.  For one thing, in the field, you can't see the target.  You don't know its depth, orientation, or type. Many, if not most of the metal detector tests I've seen start with known targets, and a predetermined position and depth.  And then, as I said, the coil is moved to obtain the centering, height and movement that produces the best/strongest signal.

In the field, you can't center the target by sight, You can't vary the depth of the buried target, and you probably won't take so much time finding the absolute best sweep speed or repeating the sweep until you get the strongest signal and most consistent reading.  I am, however, surprised by how long some take to get a consistent reading rather than just quickly digging the target to see what it is.  I'm an old man with a bad back and I still rather just dig a target rather than spend a half hour getting a reading and then getting out a pin pointer.  Just not my style.

It would be a better test in many cases, if the target, if not buried, was at least not visible or known to the detectorist until after the readings were taken.  That is more like what happens in the field, and you'd be surprised by how much something like that can affect your behavior and results.  If I know the target is a clad dime and I know that clad dimes usually produce a 22 or whatever number, that is a very different situation than if the target is unknown.  When the detectorist knows what he should be seeing, that will modify his behavior to some extent.  The difference might be a significant one in all cases, but it could be in some cases.

During most of the target ID tests I watched, the target was lying flat on the surface and the coil was moved close enough to obtain the strongest or most reliable reading.  In the field, a buried target can be deep enough that a good stable ID reading cannot be achieved. It would seem that dig/no dig decisions can be even more important or significant when the target is deeper and requires more digging, but I don't see tests that try to get an idea for deep targets or those of irregular shape or complex targets such as watches.  I've have seen some using nails to illustrate how the Manticore ID reading suggests the shape or the target.

As I've shown before, a coin on edge will not produce the same numbers as a coin lying flat. When a coin is on edge and your swing is parallel to the edge of the coin you will get a different reading on an Equinox than when you swing perpendicular to the edge.  Try it.  

Not directly related is this strange observation.  When swinging the Equinox coil parallel to the edge of the coin that is on edge, when the center of the coil is passed over the target, you will get almost no signal at all, but if you move so that the front or back part of the coil passes over the target, you'll get a signal.  It appears there is a dead spot in the middle of the coil when the coin on edge is passed under the center of the coil when the coil is moving parallel to the edge of the coin.  I believe that is because of the shape of the detection pattern for DD coils, and would not be true for concentric coils.  

Just goes to show that coil positioning can affect the signal. Regardless of the engineering and technology, it is good to experiment and observationally determine the sensitivity pattern under your coil.  I've recommended that before.

Experiementer expectations and biases can affect results in scientific experiments.  The same holds for metal detector tests. It might not in all cases be a significant effect, but it is something to be aware of.  You've heard of double-blind experiments.  Something similar could be used to improve some of the metal detector tests I've seen.  You might be surprised at how much easier it is to detect a target when you know its exact location.  When the target location is known, you always see that same signal optimizing behavior.

There are many possible effects that I won't discuss now, but I would recommend taking precautions and try to make tests relevant to field behavior.  I also recommend trying to minimize the effect of operator biases and expectations.  The fact that you are taking the time to conduct the test means you probably really want to know, so make the tests as good as you can.  If you expect or want a specific result, it is very easy to get that result.  Biases and expectations can have an unconscious effect on perceptions and behavior.

Another thing is that every metal detector, even those of the same make and model, can be different.  For example, I once had to replace a bad coil on my all-time favorite metal detector.  I replaced the coil with the same type of coil, but the first coil was more sensitive than the replacement coil. The replacement coil was an A or A+, but the first coil was an A++.  Quality control is not always perfect.

On top of everything, every detector has multiple settings, the ground and targets are different.  That makes a huge number of combinations. Generalizing is risky business.  I therefore recommend testing your own detector under the conditions that you will actually encounter in the field.  Tests should be as true to field conditions and use as possible.  

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Years ago I found a gold ring bearing a coat of arms.  New research will soon be published on the ring.  that concludes the Douglass Beach wreck was carrying a variety of present ordered by the Duke of Linares and the ring was possibly being sent as a wedding gift for Dona Maria Nicolasa. 

I'll let you know when the new book is available.

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Source: nhc.noaa.gov.

So this system is organizing some, but I don't expect a lot.  It looks like it will be staying far away from Florida but will have some small effect on our surf.  You can see that slight effect below.

Source: Surfguru.com.

The high tides are still around three feet but have decreased some since the recent peaks.

Good hunting,

Treasureguide@comcast.net

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