It seems that the metal detecting nest egg that Britain has incubated for the past decade is about to produce a chick that’s a lot bigger and uglier than PAS and others could have dreamed. 

The “depth” at which hobby machines can find most small objects has been stuck at around 5 to 8 inches for decades and everyone assumed the technology was close to its optimum. But the Minelab Company has just launched the GPX5000 – which seems to be a major breakthrough.  See this:  and this:

There seems no doubt about it, the Minelab GPX5000 can easily find small objects at 18.5 inches!

[UPDATE 26 January 2012 : in fact, 24 inches – see latest testimony from the detectorist who was the original tester in Comments]


But see this survey on the British Farming Forum, “What depth do you plough to?


Not definitive of course, (like our Artefact Erosion Counter!) but almost three quarters of the 124 respondents say they plough in the 6-9 inch range, whereas the new machine detects objects at more than double the depth of the 9 inch plough soil and more than three times the depth of the six inch plough soil – in other words more than 9 inches and more than a foot respectively [Edit– more than fifteen inches and more than eighteen inches] into the undisturbed levels! In fact, in every one of those 124 cases it seems the GPX5000 could project well below the plough soil and far into any underlying and undisturbed archaeology – as could a spade of course.


 So what are the implications?

 Well first, it seems likely an awful lot will be sold. Maximising depth has been an obsession for detectorists and a holy grail for manufacturers for forty years (see Google for proof of both) so the demand is there. Although presently expensive people are already talking of buying them on a shared basis and the history of all new technology is that the price tumbles once the new-product premium is removed, economies of scale are achieved and competition kicks in. In my view it’s not a case of whether large numbers get into the hands of detectorists but when.

 Second, it seems that this machine and similar are going to be profound game-changers because metal detecting has hitherto been tolerated in Britain on the basis that (allegedly at least) it takes place in disturbed plough soil and above the archaeological layers and is therefore relatively harmless – whereas the new machines are set to render that whole claim invalid, and this time there’s no room for argument. Who could sensibly claim that detectorists will always (or even often) confine their digging to the top few inches when they are urgently being made aware there are good targets further down. To propose such a thing would be to suggest they aren’t human. PAS oughtn’t to imply otherwise.

Third, it surely follows that there is no realistic way that PAS can tell the public there is no problem with these machines being out in their fields. It just won’t wash to say that “because we have outreached to, liaised  with, and partnered detectorists nearly all of them are now so responsible they would stop digging after a few inches.” Surely the “metal detecting debate” isn’t going to end up with PAS saying they truly believe most detectorists will practice the withdrawal method? I have news for Pope Roger: they won’t, in their thousands, and everyone knows it!

Fourth, the penny is starting to drop with some detectorists that their ability to find targets so far down is good for them but disastrous for the image of their hobby. Initial open exaltation has begun to be tempered (and moved into closed forum areas in some cases) as the realisation dawns that “We do no harm” would no longer be just a dubious claim it would be an unbelievable one that even their most loyal apologists couldn’t take seriously or transmit to the public and the government. So claims are being made about the machines being too expensive and too cumbersome and of limited interest. I beg to differ. I beg to suggest that the demand is high, that some of the criticisms are insincere and that any valid ones will be met and speedily rectified by the manufacturers, since that’s how commerce works. How about hundreds, perhaps a thousand, being swept over carefully researched areas of buried archaeology by this time next year? All perfectly legally, but followed by digging as deep and damaging as nighthawks do. Anyone want to bet against me?


So what is to be done in the face of this real and present danger to the resource?

If logic and conservation mean anything at all the Code of Responsible Detecting and the Rally Guidelines should be amended to say such machines should not be used (no, not “voluntarily used responsibly” – not used! Like sub machine guns.) And PAS should say so on the front of their website and warn every landowner not to allow them. And DEFRA should forbid their use on land subject to stewardship schemes. And no public landowners should countenance them or private landowner be left unaware of them. Indeed, if logic means anything, the importation and use of powerful metal detectors should be licensed or prohibited by law not voluntary codes. MPs and Ministers love concrete figures and a quick demo by PAS of the miracles the new generation of machines can perform ought to convince them to ban them altogether.  The argument makes itself so there shouldn’t be much difficulty: there would be no change of the status quo, just a denial of the ability of detectorists to intensify the current rate of erosion, so there’d be no valid grounds for them being angry at this curbing of their “rights” (other than frustrated greed) or being frightened on PAS’s part (other than habit). A very good test of exactly how many detectorists are truly “responsible” and how sincere our protection agencies are in their conservation aims!

But will any of it happen? Or will the archaeological establishment stay paralysed and under the detectorists’ thumbs, unable to react, as the reach of detectorists extends progressively into the archaeological layers, inch by inch?

One might think there was a bit of hope since as these machines threaten the resource they also threaten metal detecting. But trying to convince most metal detectorists that it is in their own interest to act in society’s interest is a mug’s game as I know only too well so I don’t expect many volunteers for depth-celibacy, and in the end it’s down to the authorities alone. The choice is clear, do something about it fast. Or don’t.

But rather than acknowledging that amateurs like me know owt, why not heed the words of an expert – Neil Jones, the highly experienced British detectorist who tested one for Minelab:

“It has awesome punching power and can detect to incredible depths. It just opens up a whole new level of detecting that other machines can’t touch, and that opens up lots of new ground when you think about it.” 

Or Mr Brun:

“If you are going to get one of these machines make sure your able dig deap holes” (Sic)

Or Gordon Heritage:
“It’s down to the bedrock!”

But the prize goes to “Turfaholic” for voicing what will happen:

“it’s the solution to the resource being hammered – “Interesting approach as todays finds become more rare at the 6 to 10 inch depth, this may open a whole new style to coin and releic hunting?” (Sic)

(The “solution”, nota bene, “to the resource being hammered”: This is a detectorist remember, confessing what the likes of us and Paul Barford say, and PAS won’t.  What he is saying is that emptying the ploughsoil doesn’t matter as now they can get at the undisturbed archaeology below it!)

Or maybe I should claim a prize myself for offering a moral homily that is 13 years too late and yet might still be relevant in the future:

“Never plan a strategy on the basis technology won’t advance”


Update 31/10/10 

NOTE ABOUT COMMENTS RECEIVED ON THIS TOPIC: We have received a succession of comments on this, all from metal detectorists, all telling us these machines are useless and pose no threat. Since this is so much at odds with the initial reaction on detectorists’ forums (universal delight, and many saying they would buy them) it looks very much like the comments are not to be taken at face value so we don’t feel obliged to give them a platform here. Nevertheless, here are a few examples of what we have been asked to believe. The reader can decide for him or herself whether they add up to a pretty obvious attempt to unjustly allay public fears:

I wouldn’t take too much notice of these GPX depth claims

 “I wouldn’t get in such a panic.”

Almost no-one will buy them as they’re too expensive

 “most detectorists are elderly and unlikely to wish to exert themselves to a great degree

the three people demonstrating the machine “are well known in the detecting community to be responsible”  [yet they are advocating digging to 18.5 inches?!!]

 It’s not a brand new machine, just a revamp

 “it’s not set up as an artefact finder but for hunting for gold nuggets, therefore not really that suitable for UK detecting [even though the Minelab official site says “Also great for the specialist relic and jewellery hunter who demands the best, and wants to recover targets deeper than ever before.” ?]

The previous model never really sold [so Minelab have launched this improved version expecting that this too won’t sell well?!]

people will get pretty sick of digging lots of junk at all sorts of depths”,

 “it’s mainly sales hype so the people involved can receive free detectors & other perks from Minelab

And best of all:
they are pretty much useless for most archaeological sites in Britain.”

 Well, we can all stop worrying then! Or perhaps not. Incidentally, since not a single detectorist has written to us saying other than that these machines are useless and no threat whatsoever then detectorists will have no objection to their use being officially condemned or prohibited. Will they? And if, perchance, it turns out they DO express objections (any of them) then all the more reason for doing so!

 PAS, EH, CBA, MLA, DEFRA, CLA, NUF, ALGAO, IfA and DCMS kindly note!


More Heritage Action views on metal detecting and artefact collecting