Beach Search Patterns "How do you search yours?" Part 1#

Searching beaches can present a number of problems for the novice detectorist. The beach you're planning to search could be huge! Or maybe it’s covered in signs that you read about, scallops, tide marks, cuts and so on. Then again you may be on the clock. The great thing about learning about the beaches your search is that no matter what machine you use this information will stand to you for years to come.

The Quick Search.

If you are just scouting a new location or stopping by at a beach you always liked the look of. it can be more beneficial to target the more productive areas first. Areas such as the low tide mark, towel line, paths and handy seating locations. Remember even if you're only pulling up newer coins, pull tabs and other common junk targets. These finds can be very handy when you profile your new location.

Tip: always keep a small note pad and pen handy. Sketch your new beach and mark your finds and other characteristics roughly. You can review your notes later and build a new plan of action for next time.

If the location has common markers such as scallops, cuts, gravel bars and sand riffles hit these first and see what you come up with. Take note of the feel of the sand under your feet squashy soft sand normally means you're far from the hard pack and heavy gravel under the surface of the beach.

Items will sink down to the denser hard pack and rest there and your detector may not reach the entire way pass the sand overburden. This is why beach detectorist get weak in the knees after a storm has stripped the light sand from the beach exposing the hard pack and gravel.

If you’re new beach is smooth and relatively gravel free a new search pattern is required. A repeating "W" search pattern works out best.

This works well because you can cover larger portions of the beach looking for lines of targets. If you find a target halt the "W" pattern and search in a straight line for a bit. You may have found a streak of targets or a small pocket of targets. Some detectorist will search in a spiral pattern starting from the location of the first find.

Even if you are short on time during your session take five minutes to look over the beach from a vantage point. Just like your targets you should make a quick note of anything that stands out. When you head home fire up google maps and see if what you have experienced on the ground translates to patterns found on the map view.

Normal Search Patterns

On a normal day detecting on the beach I like to search left to right from the high tide mark following the tide as it heads out from the shore. Of course if you arrive on the beach and it has some nicely defined markers or it has been stripped I like to concentrate on those markers. I still follow the left to right pattern but only over these hot areas.

If you are digging targets look for changes in the sand, gravel or clay you are digging. I always find the good targets reside in the layer of dark, almost black layer of clay. This layer is below the gravel and crushed shell layer. Normally it stinks too! So you will know it forever more after that first time. This layer is so tightly packed that metals that the sea would normally devour can survive much longer.

Periodic Table By Electrical Conductivity

Here is a very useful graph showing how conductive or restive known elements are. When metal detecting the conductivity of you target plays a huge part in deciding what to dig.

Below is the same data in a list format. I've highlighted the good stuff.

VLF metal detectors and their operating properties

There are many good explanations on how a VLF metal detector operates available all over the web. They range from very hi-tech to not so much. When I decided that I needed to have a better understanding of all the voodoo involved I knew that I would be wading through some very heady material that I was going to have problems wrapping my head around. So here are the conclusions I have drawn based on my own research I hope I've been able to lay it out in a clear and concise manner that you can understand. If you have anything of value to add, corrections or ideas please comment and let me know.

Quick overview of a typical VLF (Very Low Frequency) Metal Detector

A basic metal detector consists of a control box and search head mounted on a shaft.

The Search Coil / Head

The guts of the search head consists of two coils made of copper. One coil is the “transmit” coil and the other is the “received” coil.These are normally written as TX Coil and RX Coil. These coils are electrically separate from each other (As in they don’t touch each other) and exit the search head via a normally waterproof connector that runs along a set of wires up into the control box.

The Control box

The erm “Brain” of the machine. To be honest this little box will be your friend but also your worst enemy, well at least at the start anyway. Internally the control box consists of the detectors circuitry, batteries, control knobs, buttons, speaker and maybe a visual display of some kind. Different brands or detector will have varying names for the functions of a their detector. But VLF metal detectors as a rule of thumb have the ability to produce a noise relative to your target via the control boxes internal speaker or via a set of headphones. Ability to discriminate targets based on their conductivity. With a lot of modern machines you also get a visual display the shows numbers indicating your target this differs depending on the brand of detector you're using and even how deep it is (More on this later because nothing in life is that simple). We now know the parts that make up the detector we can have a look at how the thing actually works. The control box generates an electromagnetic field in the transmit coil. As you swing your detector over a metallic object that object interacts with the magnetic field this change in the magnetic field in picked up by the RX coil. The change received by the RX coil is slightly different depending on the conductivity and size of the target. These changes are processed by the control boxes circuits. On moderns machines much of the analyse is carried out by a processor. The processor contains software that is developed by manufactures for their machines this software is a closely guarded secret. But in general the signals generated and received are analysed by complex algorithms that are designed to give better separation between targets and also better identification of those targets.

As time marches on and technology improves metal detectors get better and better at what they do. Whatever technology proves best maybe just improved versions of what we use now or maybe there is a new technology just around the corner?

Garrett AT Pro International Mega VID Target Test List

Here are some test results that I have compiled from various sources around the internet and from my own tests.

Now like I'm sure you have read from many of the forums around the internet that the numbers are dependent on lots of variables such as was the target an air test or a reading from a target that is under ground. The condition of the target also plays a big role. Over all I find these readings useful as a starting point, they give me a little confidence in what to dig and what to ignore.

Tip: One what Id call a 'learning game' is to get a relatively repeatable signal. Then use this list to help you guess the target. To start with dig it all. This will help build your confidence when out digging.

Tip: The most common tip when dealing with the AT Pro Int is to dig everything 40+, you're still going to be digging pull tabs, bottle caps and all the other normal junk. But you're going to get all that small gold.

Cscope CS4PI Pulse Induction Metal Detector Review

Given the amount of beaches we have in Ireland (East Cork in particular) a pulse induction machine seemed to be the way to go.

The machine itself is pretty simple with an automatic ground balance system all the user needs to worry about is switching on and hitting the beach. There isn't a pin pointing mode but finding your target is pretty easy because of the concentric coil search head. Using the side step method you can get a pretty good fix on your target.

Best thing about this machine is that when it beeps there is something down there under the coil simple as that. It does suffer from the same drawbacks of other pulse induction machines there is no discrimination of any kind so just dig every target.

I've had a chance to take this detector to a location that has some very mineralized sections and as such sections are no go for other types of detectors I've used. I've taken this machine into the worst sections of the beach and found plenty of the normal junk that I'd expect to find all over the the rest of the beach. As above if it beeps there is a target that needs digging.

Other things to note.

The control unit is not water proof so just be aware of this. You can belt mount the control unit making the detector very light indeed. If the machine gets a bump it will give a prolonged beep that lasts for a few seconds (1-2) as it re balances this seems to be normal so don't worry too much when this happens.

The overall build quality is good with the upper stem being metal and the lower a tough plastic. The control box is made out of a really good quality heavy duty plastic. It can also be belt mounted (The machine is supplied with a little belt attachment). The search coil is submersible and comes with a scratch cover as standard.

Video Review:

Here is a review that I found helpful when I was making decision to purchase.

Targets Used For Testing

There are the targets I've set aside for air testing my detectors.

Target	Target Image	Note
1 Cent		Clean Coins
2 Cent		Clean Coins
5 Cent		Clean Coins
10 Cent		Clean Coins
20 Cent		Clean Coins
50 Cent		Clean Coins
1 Euro		Clean Coins
2 Euro		Clean Coins
€1		Beach Find
€2		Beach Find
20c (Euro)		Beach Find
1c (Euro)		Beach Find
1c (Euro)		Beach Find V Worn
Large Silver
Steel Tent Peg
Wine Bottle Top
Chunk of Cast Iron
Old Pull Tab (Beavertail)		(no tail)
Junk Drinks Can
Ball of Tin Foil
Piece of Worn Alu
Chunk of Very Worn Iron
Large Lead Sinker+Steel Barbs
Medium Lead Sinker
Copper Plate >.5mm
Plastic Coated Copper Wire
Old Shotgun Cap
Rusty Nail
Beer Bottle Top
Medium Fishing Swivel
Eyelet (from Jacket or Tent)
Modern Alu Pull Tab
Steel Bolt
Diecast Toy Part
Fabric Covered Button
Lead Ball/Musket Ball
Belt Buckle

Minelab Quattro Target ID Bench Test and Review

Having recently purchased a used Minelab Quattro I was left feeling a little deflated after seeing the various reviews pointing out the units slow recovery time between targets. On top of this figuring what the target icons actually related to here in Ireland. So here is the data that I have.

All the information here is first hand. Taken in all metal mode with zero discrimination.

Minelab Quattro's recovery time. Its better than you think.

Minelabs Quattro's are considered to have very slow recovery times. While this appears to be somewhat true with regards to the preset search modes that supply the user with graphic target icons. If on the the hand the user runs the unit in "All Metal Mode" the recovery time between targets is more than acceptable and on par with other brands of machines of the same approx age. Numbers on the display are more or less the same weather using conductivity or fe detection modes. Reading stability is really good for this machine I find that some other brands can jump around like crazy example swinging over a target the display may jump between 20-21 for instance, But another machine (Garrett AT Pro International) may jump to many numbers all over its display range. Granted the Garrett AT Pro is far more sensitive to the composition, Shape and size of the target.

So the bottom line is that the Minelab Quattro is a fine machine that can be picked up for a more than reasonable price, it works well on land or along the beach so I'll be hanging on to mine for a good while to come.