Thursday, February 7, 2013

2/6/13 Report - Metal Detecting Tips

Written by the TreasureGuide for the exclusive use of

It's all about the sand.  Well, not quite.  But sand is one of the biggest factors in beach and shallow water detecting.

Yesterday I visited a location where there previously was a cut and I found good numbers of coins and other targets when the water was rougher.  Yesterday, though, most of that beach had filled in but some other parts had eroded.  The sand had obviously moved from one place to another.

The short video clip below shows shells and small items being washed at the water's edge yesterday.  It is good to inspect these swash areas.  Not only might you see something of interest, but you'll also see how the moving water washes things around.

Try to remember what the beach looks like on different occasions so you can tell where the sand has moved.  A few inches of sand can make a big difference.


Identify markers such as rocks, stumps, signs or whatever will remain in the same place so you can measure the amount of sand gain or loss at that spot.

In the area where the sand had accumulated yesterday, I could often feel the mush under my feet as my feet sank in with each step.  That is never a good sign.  I hate to say never, but I feel pretty comfortable with that statement.  Mushy sand is usually a sign that you should be some place else.

The sand varies in texture and color too.  We have everything from light grey almost white to dark brown sand on the Treasure Coast, and also what we call black sand.  Black sand is usually a good sign.  I'll usually detect in any black sand.

Some people seem to have trouble detecting in black sand.  It isn't all that difficult.  You might get a few false signals until you get your detector settings right, but you can learn to deal with that.

You'll find that you get fewer false signals from black sand when you sweep with it instead of across it.  Black sand will usually be in a strip.  You can see how it was deposited by the water.

The edge of the strip will cause the most false signals. Also anything that breaks the surface, like a foot print or dug hole.

A hole dug in black sand can cause a false signal that might confuse you if you don't know how to detect in black sand.  There are a lot of snow birds detecting the beaches now that don't know how to detect in black sand.

I don't mind detecting in black sand and don't find it all that difficult.  If the layer of black sand is thin, a touch of discrimination might improve your detectors performance.

I don't mind using pinpoint mode in black sand even if the layer is thick and heavy.  Some detectors, including some of the best high end beach detectors will give a big WANG signal in black sand, but if you don't let that bother you, you'll soon learn to distinguish between the sound of the black sand and real targets.

I think one reason I use pinpoint mode than a lot of people is that I don't mind hearing salt mineralization or other subtle changes in the threshold caused by natural variations in the sand.  You can learn to distinguish noises like that from targets.

Detecting in black sand in pinpoint or all metals mode is something like detecting in the wet sand where the water is coming and going.   A lot of detectors will give false signals in the wet sand.  One way to deal with that is to adjust the sensitivity control.  Despite what the manufacturer's user guide might tell you, I never do that. I'm more likely to use pin point mode and listen to the salt mineralization.  I can distinguish signals caused by salt water from signals caused by real targets.  They haven't invented a discriminator that can compete with the human brain.

Another thing you can do when detecting in the wet sand is to sweep your coil parallel to the water as opposed to the other way.  People usually walk along the water's edge and sweep east to west.  You'll find if you sweep north to south you'll get fewer false signals.  That really isn't a problem for me.

A little practice will help you learn to understand what your detector is telling you.  Not all false signals are bad, and it is not necessary to eliminate them at all costs.  Just learn to understand them and work with them.

If you operate in pinpoint or all metals mode, you can switch to discriminate mode to test individual targets.  I think some people call that reverse discrimination.  Anyhow, it is one good option.

There are many ways to use a detector and different people do things differently.  I recommend experimenting and trying different things.  Get to know your detector better.  You'll learn more if you take time to experiment and try different things.

A 300 year old family Bible was stolen, sold for over $400 and eventually tracked down and returned.

Here is an article showing some of the artifacts, including coins, discovered at the De Soto site near Ocala.

On the Treasure Coast Thursday will be another day of calm seas and nice weather.  The surf will be around one to two feet. 

This weekend the surf will be increasing.  The peak is predicted to be Monday, reaching 4 - 6 feet.  That will be a little different even if it isn't normally enough to significantly improve detecting conditions for old shipwreck items.  It might help a little.  We'll have to wait and see.

Happy hunting,