9/12/19 Report - Coil Awareness and Gridding. Could Be New Storm Forming Not Too Far Away.

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

Source: nhc.noaa.gov

Here is one to watch.  The one nearest to us will likely strengthen and could become a tropical storm in the next day or two.  I'll be keeping an eye on that one.

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Detectorists often talk of gridding.  I take that to mean that they thoroughly and systematically covered an entire area inch by inch, not leaving any part of that area uncovered.  Sometimes they don't mean it that way.  Sometimes they mean what I would only call a lose grid, which may not cover every inch but still employs an up and down and back and forth pattern.

Above you see what I would call a grid pattern.  The detectorist would start at bottom right and work bottom to top sweeping the coil right to left and left to right up the first column and then moving over and coming back down the next column, repeating that until the entire area of interest has been covered.

If you have a ten inch double-d coil, each step you take before changing the direction of your sweep should be ten inches or less, otherwise you would be skipping some area in your grid.

When I'm not worried about covering every inch, such as when I am just sampling an area, I might call that a lose grid.  When I do that, I'm OK with missing a little.  I'm just scanning an area to see how promising it might be.

The illustration above is unrealistic in several respects.  First, it would be very difficult to make such perfect straight passes with a metal detector coil.   That would be quite unnatural and would require you to move very slowly, deliberately and unnaturally.  The natural swing would be an arc - not a straight line.

The illustration immediately above is not totally accurate either, but shows what would be a more typical arc-shape coverage pattern.   The red arrows point to some of the ground that is not covered by the detector coil.  If you walk faster and sweep while moving, you'll miss more ground.  It takes a lot of discipline to not miss skip any ground.

It can be surprising to learn how much ground you are missing.  I recommend throwing a target or two over your shoulder and then turn around and detect without looking at the ground.  You might be surprised by how often you miss an easy surface target.  I've demonstrated that to myself on multiple occasions over the years.

In actual practice, if you are holding your metal detector with your right hand, the arc would be tilted more to your right side.

The primary pivot point for the arc of your coil sweep would probably be your shoulder.  Often your elbow will be another pivot point, and also your waist.

If you consider how you actually swing your detector, you would not be walking down the middle of the path covered by your coil because the more of the arc would be to your right if you are holding the coil in your right hand.

The following illustration shows how your sweeps will be more to the right if you are holding your detector in your right hand.  To cover the entire area well, the distance between your north and south paths will not all be equal.  The first north and south paths are farther apart than the first south and second north path because the sweep is longer on the right of the detectorist.

Path Adjusted For More Complete Coverage Without Much Overlap

Here is an rough illustration of what I would consider a fairly normal sweep.

Note how much more of the sweep is to the side of the hand and the greater length of the sweep on the right partly due to the north to south movement of the coil as well as the east west movement.  That can be used to advantage when are walking parallel to a cut.

Of course different people will have a different sweep and may vary their sweep at different times.   I find it useful to be aware of how I am sweeping and will change it for different situations.

By paying attention to the biomechanics, you might be able to hunt tighter, longer, without becoming tired so soon, and [prevent overuse injuries.

There is also the matter of the vertical movement of the coil, which is just as important.  It is not uncommon for people to lift the coil at the end of sweeps.  That can cause more false signals and reduce depth to the extent that targets are missed.

The type of sweep you use is up to you and might change with the situation, but I think it helps to be aware of your sweep pattern.  You might want to take your detector out to the beach and sweep it on the dry sand just to see the pattern you make.

I'm sure nothing I said today is very surprising, but it is one thing to know something and another to apply it.  I have to remind myself once in a while.

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Terry asked me if that wasn't a Mexico style cross on the reale I posted the other day.  I took another look, and it does seem to be the Mexican cross.  I thought it might be a Potosi reale before taking a closer look.

Thanks Terry T.

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Keep watching the Atlantic.

Happy hunting,
TreasureGuide@comcast.net

2/26/16 Report - 11,000 Year Old Pendant Found. Button For ID. When to Grid.

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

"Silver" Button For ID.
Find and photo by Tom G. from Delaware.

Front of Same Button.

This button was found by Tom G. in Dover Delaware.  If you can provide any ideas about possible age or identity, please let me know.

I also received pictures of a very old cannon to identify.  I hope to be able to post that soon.

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Here is something really interesting.

"An 11,000 year old engraved shale pendant discovered by archaeologists during excavations at the Early Mesolithic site at Star Carr in North Yorkshire is unique in the UK, according to new research."

Here is the link for the rest of that article.

http://www.york.ac.uk/news-and-events/news/2016/research/mesolithic-shale-pendant/

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Gridding can be useful in some situations, however it can be a big waste of time in other situations.

Gridding, to be done well, is done in a very tight pattern.  When gridding is appropriate, the boundaries of the area should be defined and marked, and you should be able to see or keep track of the areas you have already covered well.

There is simply too much area on a beach to cover an entire beach.  A team of detectorists might choose to grid a section of a beach.

Gridding is more appropriate when the area to be covered is small and well defined, such as at an old home site.

On a beach, there will be different areas.  Some of them will be much more promising than other areas.  If you decide to grid, you will want to spend your time only on those areas that are the most promising.

So how do you find the best areas?  One is by recognizing the signs when you look at a beach. Another way is by knowing the history of the beach.  And another way is by sampling.

Signs you might want to look for can include things like dips or cuts.

Other things to look for include high traffic areas, such as walkways, beach chairs, or vendor booths.

High traffic by itself is not the only factor.  Not all traffic is the same.  Generally speaking, the more active the population, the better.  Activities such as parasailing, jet skiing or volleyball can cause  lot of losses, so look for areas where people are not only present but also active, especially in the water.

I do a lot of sampling.  Even the busiest areas can be cleaned out on a daily basis, or even more often than that.  Before committing the time to run a serious grid pattern anywhere, I want to know that there is some reason to spend a lot of good time at that location.  To test an area, I will run a loose pattern of some sort to see it it looks promising at all.

There are times when you might want to go after a high value target in an area where there really isn't much else to be found.  If there is the possibility of a very high value target, there are times when it could pay to grid the area thoroughly even if there aren't any other targets.

I discussed basic metal detector math in a post back some time ago.  One high value target can be worth thousands of low value targets.  If have good reason to believe there might be a high value target in the area, it doesn't really matter if there is nothing else to be found there.

My main point is that before deciding to grid an area, especially on a beach, I need a good reason to spend my time gridding that area instead of spending my time somewhere else.

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On the Treasure Coast the wind is turning into a north wind, however we'll have a couple of days of very smooth surf.

Happy hunting
TreasureGuide@comcast.net