4/17/19 Report - Seeing Beaches, Cuts, Bars and Dips Form. Reflections on Cathedral of Notre Dame.

Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

I have an free Easter present for you today.  It is a little early. and it wasn't what I planned on doing, but it is just too good.

I'm going to show you an excellent wave tank video.  It begins with small slow waves and increases the frequency of the waves and then the size of the waves. You will get a really good look at how waves of different frequencies and sizes affect a beach differently.

There are some things I want you to watch carefully, so I'll give you advance warning.

Here is a clip that comes from the beginning of the video when the waves are small and the time between them is relatively large.

Small Infrequent Waves Building a Beach.

Notice how the sand is agitated in the high energy area where the wave is breaking.  I've mentioned this before, but this is the best illustration that I've seen.  You can really see the sand being suspended.  The suspended sand is then dropped on the beach as the water slows on the slope.

Suspended Sand Under Front of Wave.

You can really see how the sand is suspended in this clip  That sand moves back and forth as the wave passes, almost seeming to vibrate.  If you watch it in the video, you can see how similar it looks to the liquefaction video that I posted yesterday.  You can really see the similarity when the waves are more frequent.

While there is a lot of sand movement both ways in that area, there is a net movement either landward or seaward, depending upon the size and frequency of the waves.

When the frequency is increased,, you'll see the sand start to erode.  A small cut is created when the waves are frequent but not large.

Then when the waves get bigger, the whole thing accelerates, and a lot of sand migrates down the slope.

Bigger Waves Has Moved Sand Down The Slope And Has Created a Sandbar.

Notice also the dip.  That is an area that can expose a lot of objects on a beach, especially when the dip is down close to a hard rock or clay bottom.  That can be a real bonanza.

In the last clip, the sand has been completely removed from in front of the end of the tank.  That is how it would work if there was a sea wall or something behind a beach.  A sea wall will accelerate sand loss, as will a cut.

Now watch the video and you will see how all of those things develop.

https://www.youtube.com/watch?v=SCirBRjYKSo

If you watched the entire video carefully several times, you probably got a lot out of it.

I watched it quite a few times and will probably watch it several more times.

Again, a wave tank is not exactly like a beach, but you will find some things the same.

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I wanted to comment on the Cathedral of Notre Dame.  We all saw the images.

Alain de Botton, author of the The Art of Travel said, “A dominant impulse on encountering beauty is to wish to hold on to it, to possess it and give it weight in one’s life. There is an urge to say, ‘I was here, I saw this and it mattered to me."

I lost the original reference, but I read the following in a current article. Maybe it was the New York Post, but I'm not sure.

… In a world that increasingly feels impermanent, transactional, brittle and under threat, the stillness and solidity of an 850-year-old steeple stretching into the sky gave us hope that some things remain. That how we once were is how we will always be.

Indulgently, these monuments are also a backdrop to our younger, more adventurous selves. They remind us of who we were when we fell in love or explored with friends or opened ourselves to long unscheduled weeks in unfamiliar lands.

You cannot gaze at a shimmering stained-glass window or find yourself dwarfed by a sepia-toned fresco and not feel sharper, rawer, as if in glimpsing beauty it is indelibly etched on your soul.

I think that is all pretty true, but watching it burn and crumble, reminds us that all things in this world, the most wondrous and long-lasting, will eventually crumble and fall.  In that we recognize our own mortality. And in the thought of rebuilding, we share the joy of resurrection Sunday.

Happy Easter!
TreasureGuide@comcast.net

3/29/15 Report - Importance and Method Of Determining The Shape Of The Area Of Target Sensitivity For Your Metal Detector Coil.

Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

Every once in a while I post information that you won't find anywhere else.  Sometimes I get deeper into a topic, or sometimes I approach it a different way.  Today I'll post something I bet you've never heard before, at least not in the same depth or the same way.

Before getting into the new stuff, I need to repeat a bit that I've posted before.  Here goes.

There are several problems with air tests.  An air test can be useful when you get a new detector and are just beginning to get to know a detector and how it responds to different types of targets.  You can't, however, judge how deep a detector will detect in the field from an air test.  I do recommend doing some air tests to begin with, but field tests are much better.

One of the problems with an air test is that people test targets directly under the center of the coil in order to get the maximum depth.  In actual use in the field, the target will often not be under the exact center of the coil.

Also, when conducting an air test, people adjust the speed they move the target so they get the greatest possible depth. In the field, most people do not use the optimal sweep speed.  That can make a big difference. 

An air test can be useful for learning what type of signal, if any, a target will cause.  It can also give you an idea of the relative depth that can be achieved on different targets in air.

A third use, and here is one that you probably haven't read or heard about before, is determining the shape of the area of target sensitivity under the coil.

Illustration Showing Coil and Two Different
Areas Of Detection Sensitivity.

In this illustration the area between the curved red line and the coil would be the area of target sensitivity for a coil that is not extremely deep-seeking.

The area between the green line and the coil would be the area of target sensitivity for a more sensitive coil.

The semi-conical shape would be a very common shape for the area of target sensitivity for many detectors. 

Usually the greatest depth is achieved under the center of the coil.  Less depth is achieved out closer to the edge of the coil.  That is common knowledge.

The shape of the area of sensitivity is different for different detectors and different coils.  The area of sensitivity is more narrow for some detectors and broader for others.

I've had some coils that are more sensitive than others, even on the same detector.  One particular coil that I had was very good at picking up objects slightly outside of the edge of the coil.  Some people might say that isn't possible, but I'm convinced that some coils/detectors/settings can do that.

Coils that are good at detecting good targets at the edge of the coil, or even beyond the edge, have what I call good peripheral sensitivity.  You might think of that as being something like peripheral vision.

The Whites Surf PI, as one example, is much more sensitive near the center of the coil and not very sensitive out away from the center of the coil.  The area of maximum sensitivity is narrow on that detector.  That means that if you want to get good depth, you have to overlap your sweeps a lot.  Otherwise much of the area you cover will only give you something like half the depth or less than what you will get under the center of the coil.

In the above illustration I have four targets.  One would be detected by the less sensitive coil, one by the more sensitive coil and two missed by both coils.

Now here is an important point.   Since the size and shape of the area of target sensitivity is different for different coils and detectors, it is useful to know the approximate size and shape of the area of target sensitivity for your coil and detector.  One way to determine that is by air testing.

To determine the shape of the area of sensitivity for your coil for representative targets, do an air test, but instead of trying to find the maximum depth at the sweet spot, run your test target under the coil in the middle AND ALSO at different distances out from the center of the coil.   You will then learn the approximate shape of the area of target sensitivity.   How narrow or broad is the area of target sensitivity?  How broad is the area of maximum sensitivity?  How close to the edge can you get decent depth on the types of targets you are interested in?

Illustration Showing Three Sweeps, Two To The Rigth & One To The Left

This above illustration isn't very good, but I tried to do it quickly and the tool I selected wasn't great for the purpose.  I hope you can figure it out.

The circle labeled "coil" represents the starting location of the coil before the first sweep.  The big red rectangle shows the area covered by the coil as you sweep to the right.  The green rectangle shows the area covered by the coil on the sweep back to the left, and the blue rectangle shows the area covered by the sweep back to the right.  In actual practice these would most likely be arcs instead of rectangles, but I hope you get the idea.

The yellow area in the middle of each larger rectangle represents the area of greatest depth and sensitivity near the center of the coil.  Even with this tight sweep pattern some small area between the second and third sweep is not covered by the coil at all.  There is some overlap at the end of the first sweep and beginning of the second and some overlap at the end of the second sweep and beginning of the third.

The area of maximum sensitivity and depth (yellow) is more narrow than the width of the coil.  That means that even if you run a tight sweep pattern, the majority of the area covered by your coil is actually getting less than the maximum depth. 

With detectors having a narrow area of maximum target sensitivity that is more serious.  You would be getting much less than your maximum depth in most of the area you cover.  That is why it is important to know the shape of the area of target sensitivity and the areas of good and poor sensitivity for your detector   You can then adjust accordingly.  If it has a narrow area of maximum sensitivity, you might want to overlap more.  If your detector has a good broad area of sensitivity, you won't need to overlap as much to maintain good depth. 

Different situations call or different strategies, but you have to know your detector to make the very best decisions.  Knowing your coil and its response characteristics and strengths and weaknesses will help you make the best decisions.

6/414 Report - Half Cent, More Glitz, TV Treasure Hunt, Queen's Coach & Three Characteristics of Metal Detector Signals

Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

Find and photo by Steve S.

Steve S. is from Iowa, but like many detectorists, visits the Treasure Coast where he does some metal detecting.

Here is how he found this half cent.

He said, Went out last Sunday to a nearby village and detected a residence built in the 1840s. This 1829 Half Cent was all that I found. Nice shape for Iowa.

That is a very nice find.  In uncirculated condition it would be worth well over two hundred dollars.

Congratulations Steve!

Photo of find by Steve S.

Half cents are rare finds.




Here is a web site that discusses and gives values of half cents.

http://www.coinstudy.com/half-cent-values.html





NBC's Today Show has been having a daily treasure hunt.  They hide an envelope containing prizes in the city of the day and then give clues to where the envelope can be found.

http://www.today.com/allday/al-roker-launches-todays-treasure-hunt-inspired-hidden-cash-craze-2D79739309



The Queen of England got a new coach.  It is Covered in around 400 books of gold leaf, it contains timbers from king Henry VIII's flagship the Mary Rose, which sank in 1545, and Isaac Newton's apple tree, which inspired him to form his theory of gravity.

Here is the link for more about that.

http://news.yahoo.com/queens-state-coach-encapsulates-british-history-220653016.html

Timbers from Henry VIII's flagship!  Is that saving history for the public?   Maybe it is.  Doesn't seem the best use to me.

Find and photo by Robert H.

I've been showing some of the finds of Robert H. lately.  I posted his trash finds one day too when I was talking about how much trash is picked up by detectorists.

Here is another one of Robert's finds.  This one is really glitzy!

Congrats Robert.  





A few posts ago I was talking about signal detection theory as it relates to metal detecting.  I talked about how signals usually exist in a field of noise.  I wanted to talk a little about three features of good signals when you are using all-metals or pin-point modes.

First, of course, is loudness.  Obviously a loud signal will tend to stand out, but not necessarily, if you have a lot of noise, including a very rough threshold or poorly ground balanced detector.  Increasing volume can increase noise as much as the signal and therefore won't necessarily be of much help.

Signal loudness, when considered in conjunction with other variables, can tell you something about the depth, size and composition of a target - even in all metals mode.  Of course shallow targets will tend to be louder.  Larger targets will tend to be louder.  And more conductive targets will tend to be louder.

Distinctness is another quality of a signal.  Signals will be more distinct (have a more sudden onset and termination) sound, when the target is more shallow.  Distinctness will generally make a good signal easier to identify in a field of noise.  However, as the target gets deeper the signal will appear more smooth.  It will not be as loud and will not be as distinct.

A third signal quality is duration - how long the signal remains loud as you sweep your coil.

You can get a very good idea of how shallow a target is by combining these three signal characteristics.  A small target near the surface will be loud and distinct.   The duration of the signal will, however, vary depending upon the size of the target.  Duration and distinctness, as I've defined them are different things.

A deeper object of the same size and composition will produce a signal that is not as loud and not as distinct.

A larger object of the same composition at the same depth will produce a signal that is as louder but the signal will not be as distinct, and the duration will be larger (The signal will be more spread out.).

If you sweep multiple times over an object in all metals mode and vary the direction of your sweep, you can get some idea of its size and shape.

One peculiarity that I've talked about before is the double signal produced by narrow long objects such as nails when you sweep in one direction and single beep when you sweep at 90 degrees to that.  I've gone over that in detail in the past.

With practice you can use your detector in all metals mode to gain a lot of information about suspected targets from the loudness, distinctness and duration of the signal.

Back to the signal in noise problem.  Signals giving faint signals are more difficult to detect in noise, as are signals that are less distinct.   Faint indistinct signals will often be lost in noise such as that created by black sand and salt mineralization or even an erratic threshold tone, however you can easily detect near surface objects in black sand from the more distinct signals. 

Learn to understand what your detector is telling you.  It might be saying more than you would guess.


I showed a photo of two detectorists on a beach a day or two ago.  They wrote in.  The detectorists are Tim and Betty M. 

Thanks to all of you who write and submit finds and information.  I really appreciate it.


On the Treasure Coast the surf today is three to five feet.  The surf will be decreasing the nest few days and we'll be back down to something like a two foot surf.  Don't expect any improvement in beach conditions.  The tides are pretty flat now too.

Happy hunting,
TreasureGuide@comcast.net

8/27/13 Report - More On Secondary Detecting Sites and Their Surprises & Experimenting to Learn More About Your Detector

Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

Here are three beach dug 14K rings of different sizes.  There is quite a bit of difference in the surface area and amount of gold in each of these.

I recommend taking rings of different sizes, putting them on the ground and scanning them with your detector.  Listen to how much different the signal is for each ring.  I highly recommend practicing with your detector like that.  Move your coil different distances above each ring.  Notice at what depth each drops out.

Then vary the settings on your detector and observe the results.  Increase and decrease sensitivity and notice where each drops out.  Increase and decrease discrimination and see how that affects the signal at different distances.

I think people do not do enough of this kind of thing.  It is a good way to learn how different detector settings affect the results, it is a very good way to learn what your detector is trying to tell you.  Of course the results will not be exactly the same under different situations in the field, but you will still learn a lot about how to use your detector.  I'll bet a lot of you find out that you might have been missing items like the very thin ring because of the settings you use.

This experimental method is much better than simply using the factory settings or doing what someone else says.




Now I want to recap some of the main points that I discussed concerning the four old coin spots that I talked about two days ago.  Those old coin spots are very much like the shipwreck coin sites of the Treasure Coast.  They appear when conditions are good and disappear when beach conditions are not good.  They primarily produce a particular type of target that comes from an older source even though targets from other sources as well as more recent losses can sometimes be mixed in.

Deciding if you want to spend time on spots like these old coin spots ,might include several factors such as the expected quality or value of finds, the expected frequency of finds, and other possible risks or costs such as the time risk of missing out on other promising sites, but with this type of site the most important factor is the beach conditions, which can cause the probability of finds to vary from near zero to very high.

Another important characteristic of those four coin spots is how quick and easy it is to check those sites.  You could quickly take a look to see if they might be producing or not, and it would be quick and easy to check out the well defined area with a detector, and if producing, do a good job of cleaning out most targets before moving on.

As a result, sites like this are good supplementary detecting sites, or when higher quality sites are not producing for one reason or another, they can become your first choice.  When better sites are producing these secondary sites can wait.  There is little chance that anyone else will clean them out, although there is the danger that conditions might deteriorate.

You can see that the decision making process to maximize the value of finds can be more complex and precise than simply always checking out your same old favorite spots or some simple-minded site rotation strategy.

The primary value of these old coin sites is that they can supplement other hunting when you are in the area or passing by or when you are waiting for a tide change or something before hitting higher quality sites.

Much of the above discussion assumes a goal of maximizing the monetary value of finds.  That might not be your only goal.  Some people simply like old coins or some other type of target and like to find those types of targets even if they are not the most valuable.  Some people also just like to explore.

One thing to remember about these old coin holes is that they also occasionally produce surprises.  And some of them are associated with other locations that produce other types of targets.

For example, near spot 2 there was and still is a series of groins in the water opposite the dunes.  The shallow water seldom produced jewelry of the age of the coins.  I believe that any older jewelry, if there was much to start with, which would probably not have been expensive anyhow, was probably pulled into the deeper water that rushed through the cut just off the beach.  There was however an occasional more modern gold item that was found in the shallow water there even though very few people visited that area during the period that I was detecting the area.  Nobody that I ever saw detected that area and so if something was lost there it stayed there until a storm came along to pull it down into the deep water.  One of the good things about areas like this is that they don't get cleaned out on a regular basis.

Spot 1, the modern jewelry hole that I talked about the other day, was like that too.  In my estimation, there wasn't a great deal of jewelry lost there, but it would accumulate for a while without being cleaned out.  Again, that is the good thing about finding your own little spots, as hard as that might seem.  You can let them accumulate and clean them out pretty much on your own schedule.  I know that is difficult today, but it can still be done.  There are good stretches that almost nobody detects.  You do have to do what I've been talking about - not following everyone else but taking time to explore and find those areas that aren't heavily hunted that do produce under certain circumstances.

I mentioned the other day that genuine treasure chests have been discovered not far from these locations.  Other old artifacts have also been discovered in the past down around there.  When you are out in an area with a long history, you never know what might pop up.  That is another reason to go out and explore a little.  Sometimes these types of coin spots are simply a part of the mix that keep it interesting while you are looking for other things.

I should remind you that some of these sites have changed in more recent years.  A lot of construction was done on Virginia Key.  The white sand dunes were flattened and removed, as one example.   That does not change the general principles that I am illustrating.  My intent was not so much to give you specific locations but to illustrate general principles that can be applied anytime and anywhere.


There are no storms right to watch right now.  This morning some heavy showers came around Fort Pierce near low tide, which was just after 7 AM.  They didn't last long.

The surf is running about 2 - 3 feet today and will decrease a little for the next few days.

We've really had a couple of years with very few periods of good cob hunting along the Treasure Coast.  Things come and go in spurts.  I'm expecting this long dry spell to end some day.


Happy hunting,
TreasureGuide@comcast.net