Many archaeologists believe they are a vital part of their work, while some dismiss them as mere treasure hunters. Now a new code of conduct is recognising the role of metal detector enthusiasts in mapping the UK's history.
For anybody who encountered one in childhood, the strange whistles and beeps of a metal detector conjured up a special kind of magic.
Each noise from the contraption would generate a wave of excitement that would subside only when one realised that the unearthing of a rusty horseshoe or drinks can would not lead to a call to be the next Indiana Jones.
Most children became disenchanted when repeated sweeps of the back garden failed to unearth the next Sutton Hoo.
But there are tens of thousands in the UK whose initial excitement has never worn off.
These metal "detectorists" spend their weekends braving driving wind and rain, and have been responsible for a series of spectacular finds in recent years.
What links these five finds is that they were made by responsible detectorists who quickly notified the authorities so the archaeological context could be preserved and the site properly excavated.
Mr Bradshaw says he did not consider himself an amateur archaeologist, but had got a unique thrill from unearthing the Ringlemere Cup.
"It gives you a feeling you can't put into words. I'm so pleased and proud. The cup is only the second one ever found in this country. It was mind-blowing."
The detectorist says he was in the area looking for a Saxon burial site, prompted by his discovery of Saxon items, and was baffled when he discovered the cup, at least two millennia older.
"That is how most items are found, by chance, by a chap going around.
"I didn't do any more searching or digging - I would have been destroying the context."
Mr Bradshaw and the landowner shared a £250,000 reward and he admits an element of luck is important.
"You can go across field after field, year after year, and some people don't find anything of significance.
"There are different types of metal detectorist. [You get a] type who go out with the full intention of earning some money. They will find it and flog it.
"There are right criminals who will go on land during the night."
To ban or not
It is this minority element that has harmed the image of metal detectorists in the past. In many European countries detectorists are not allowed to operate in order to protect antiquities, but the practice still goes on clandestinely with finds ending up on the black market.
Britain has always had a more tolerant position, although the Council for British Archaeology fought a campaign to ban metal detecting in the 1970s. Things have changed dramatically. Now they are backing the voluntary code for the hobbyists and recognising their role in archaeology.
Dr Mike Heyworth, director of the council, says the archaeological fraternity had changed its mind.
"The council in those days took the view metal detecting [by hobbyists] should be stopped and banned. We now recognise the detector is a tool that can be used."
The council has driven the creation of the code of conduct, which as well as encouraging responsible behaviour is a recognition that the hobby has a right to exist and a role to play.
It is the first time landowners, archaeologists and the detectorists themselves have been able to agree common guidelines.
Finds as spectacular as the Ringlemere Cup are vanishingly rare, but thousands of items, many mundane, and many not metal, are reported to the Portable Antiquities Scheme - based at the British Museum - every year.
In 2004-5, about 40,000 finds were reported and this rose to more than 60,000 last year. Most are not precious metals, but many are significant to archaeologists and historians in some way.
Code of conduct
Before their first spot of detecting, searchers are warned to get the agreement of landowners, and establish how rewards for a find will be split, as well as making sure they know the rules on protected sites.
The code says the detectorists should confine their activity where possible to ploughed land, or areas otherwise disturbed, and to minimise any further disturbance through the use of appropriate tools.
They must record accurately where finds are made, to at least a 100m square area. Most importantly they must notify the landowner, and with their permission in the case of items not classed as "treasure", the authorities - the PAS or local finds liaison officers - as soon as possible.
Modern ploughing has been blamed by some for damaging antiquities such as the Ringlemere Cup.
Michael Lewis, deputy head of the PAS at the British Museum, says liaison with detectorists is the way to ensure vital evidence was saved for posterity.
"About 90 percent of all archaeological finds come from ploughed land. In effect people doing metal detecting are recovering these items before they're smashed to bits."
And the force of detectorists, estimated to be 30,000 strong, provide two other avenues of help for archaeologists.
Dr Lewis says most digs now use metal detectors, and some chose hobbyists to operate them because of their proficiency with the kit.
And the random nature of detectorists' sweeps offer "different sort of finds where archaeologists haven't normally been to provide clues about new sites".
Glimpse of past
Bob Baldock, vice-chairman of the National Council for Metal Detecting, says his members have helped build up a map of finds.
"In my local club we are trying to paint a picture of Warwickshire. Archaeologists finds are selected sites, castles, villas, but some of the best information is from the random finds, random losses from the population in the past."
But archaeologists do know the consequences of rogue treasure hunters armed with metal detectors descending on a valuable site.
In the 1980s details of a find of coins at Wanborough became public and sparked a frenzy. The site - believed to be a Romano-Celtic temple - was left a patchwork of holes by treasure hunters who stole up to 10,000 coins. Police only recovered about 1,000.
Since 1996, the legal position has been easier for detectorists. That year's Treasure Act makes the process for gold and silver finds over 300 years old absolutely clear.
The finders and landowners can expect to be paid market value for their discovery - after an inquest and valuation - which has led to some big rewards and given a great incentive for the most valuable finds to be reported.
But for most the pleasure of finding something historic is all they need. Mr Baldock says his favourite item was a Bronze Age axe head.
"It was 4,000 years old, and finding it was a great thrill. There is no [cash] value in the item, except it is one of the oldest metal items around.
"To find an axe from the Bronze Age is pretty exciting, and sharing it with the other club members, everybody having a look and a feel of it."
This weekend the metal detectorists will be continuing their work, whatever the weather.
As Mr Baldock says: "I've seen people going out in snow and wind and rain. Nothing stops us."
Here are a selection of your comments.
I have been metal detecting on & off for 40 years. I retired 5 years ago and have found metal detecting both rewarding & healthy. I belong to a metal detecting club & a Archeology club. We do "Battlefield Archeology" and are called upon by many other USA states to do metal detecting (dig, flag & tag) for other archeologists. We also are called upon by local police to help locate evidence at crime scenes.
Yes, there are "night bandits" who pillage for treasure & money but every organization has its bad apples. Government has its "bad apples" but the majority is respected for what they do. So don't just pick out the worse of some detectorists and call the whole hobby as being bad. I only wish that the USA would revise its laws in a positive way pertaining to metal detecting.
Russell, Old Bridge, New Jersey USA
Speaking as someone who will complete his archaeology degree in a few weeks, I'd like to mention that archaeologists, and their funding, are more often than not stretched to their limits by what and how thoroughly they can examine a site. I feel that, especially in situations where fields are ploughed regularly, searching by metal dector may at least turn up sites that would have otherwise been destroyed or overlooked. Context in an archaeological site is of utmost importance; digging to reveal the artifact will, in most cases, damage at least part of the context, which cannot be recovered once disturbed. Far more knowledge is gained from knowing how artifacts relate to, and were found in their surroundings than an individual object on its own. Obviously, however, an archaeologist cannot be summoned for every object found, and it seems reasonable that the detector carefully uncover the object to determine whether it is worth reporting.
Van, UCLA, Los Angeles, California
Metal detectorists are responsible for contributing a wealth of knowledge to enhance local and national history for future generations to enjoy. Our small group of detectorists have submitted a number of finds to both the local and national museums as our part in building up a national picture of our past.
We are all custodians and as such have a resposibility to add all possible knowledge to our national heritage data bank. A number of our land and farm owners have boxes of items that we have located on their land many of which were left behind many hundreds of years ago. It seems to me that it makes good sense that as many items as possible should be preserved and cherished and not left to rot in the soil. Many of our finds and locations are allowing the archaeologists to follow up our initial leads to sites of potential significance.
Jerry Morris, Bristol
The PAS strikes me as a wonderful example of the good that government can accomplish. As to the "magic" of a find... I so well remember the first time I held a fossil in my hand! Wouldn't it be wonderful to get the school children of the UK involved in the detectorist's hobby? So many lessons could be taught! Respect for the land and the past. How effort doesn't always deliver immmediate rewards. How close observation can be its own reward. On lucky days: how keeping careful records can be very, very important!
Curt Carpenter, Dallas, Tx USA
Just to clarify for Richard Dunning - the Portable Antiquities Scheme makes available the detail of finds available to Historic Environment Records - with data being available for download into the local HER database.
David Dawson, Oxfordshire
Do the detectorists that scan the beaches in the summer hand in any items they find at the local police station so their owners can claim them?
My detecting enjoyment is often marred by thoughtless people who ruin the solitude of local parks by playing sport, running and shouting and digging up divots with their football boots and golf clubs. Some of these idiots even deliberately drop metal objects in my path to see if the machine really works.
As a child I spent many weekends with a metal dectecting club. It was fun, interesting and exciting. You never knew if that bleep in your headphones signified a drinks can ring pull or a Roman coin. Sadly I never found anything more interesting than Victorian coins and one or two lost wedding rings. I appreciate people raising concerns about irresponsible detectorists leaving turf dangerously cut up but the majority of detectorists search ploughed fields. They are a valuable aid to archeologists and you only need to look at the declared finds over the past few years.
I am an archaeologist and have always had good experiences with metal detectorists especially alongside field walking, however a Roman site that a friend was digging was destroyed by nighthawks (illegal detectorists). They picked up a signal under a roman tessellated pavement and hacked through it, destroying it forever, the find? A piece of roman lead pipe which they left in the hole. Simply senseless destruction of our heritage.
Simon Woodward, Leicestershire
When used responsibly, metal detectors can be a very useful tool. In my field of study, Early Saxon Economics, they have provided the best set of data available, and have proved the existence of a network of inland temporary markets form the end of the seventh century. Vast numbers of coins have been recovered, and distribution patterns and mints and issues can all be studied in unprecedented detail.
But there are a couple of qualifications here. Detectorists only uncover non-ferrous metals. Only detailed excavation, which produces ceramics, bone etc, can allow the metal objects to tell their full story. It is not feasible to excavate all sites found by detectorists, but it can tell us which are the ones worth digging. Another qualification is that not all objects are reported, as many, like the metal scrap I am looking for, have no intrinsic value and do not appear on the Portable Antiquities Scheme database. So If you find a piece of scrap silver or copper-alloy in connection with a coin or strap-end, please report it to your local archaeologist. Even things of no intrinsic monetary value are worth studying.
Mark Errington, Hereford UK
Sorry to hear that Mr Stevens had such an issue with detectorist. I do however disagree with his solution (probably a Time Team follower) in seeding any land. This is as irresponsible as a detectorist leaving a hole open in the ground. In doing such a thing you will distort any archaeology that may be under the ground that may be dug at a later date.
Do we stop people playing football, rugby or indeed horse riders in parks because they disturb the ground too!? Metal detecting is a legal and enjoyable hobby, how many more rules will it take to satify those in high office before we go the way of the hunting and shooting(hand guns) fraternity?
Peter Twinn, Nr Bristol
After reporting finds to the Portable Antiquities Officer please also pass on the information to your local Archaeological Record (called Historic Environment Records) in your local council so that the discovery can become public knowledge. The Portable Antiquities Scheme keeps the exact location secret which makes it pretty useless at a local level, so take the extra step and really help our understanding of the past.
Richard Brunning, Taunton
..."going out in snow and wind and rain. Nothing stops us"... that applies to golfers, too.
George Deeming, Kennesaw, Georgia
As a professional archaeologist, I've been dealing with detectorists for 25 years, working alongside them on sites, liaising over finds etc. Correctly used the machines are a valuable tool, and many detectorists are extremely skilled and methodological in their approach, with some now using hand-held GPS to locate their discoveries.
The problem is many of the more casual 'hobby' users do not report finds, or provide only general locations. Collection obviously tends to be skewed towards metalwork, whereas archaeologists are interested in the whole picture, including pottery, building material etc, which may seem tedious, but helps to identify and characterise occupation sites. The PAS and metal detecting clubs between them have done a good job in improving relationships and reporting, building on best practice set up over the years by museums and more progressive archaeologists. Hopefully that process will continue, as there is room for all.
T. Brigham, Hull, UK
So called detectorists are an absolute pain on our local urban park. They should be prosecuted for criminal damage. They leave holes and damaged turf all over the place. People doing sports or playing in those areas are then at risk of breaking an ankle. We have found that seeding the soil in the area with hundreds of washers of different metal types is the best way of getting rid of these pests.
Chris Stevens, London UK
It's so refreshing to have clarifying ground rules for metal detecting. Now all we need is to attract more women into this amazing hobby!
Catherine Coulthard, Solihull, England
When I was much younger, my father hired a metal detector for a week or so, just to have fun, and we found nothing more exciting than a bottle cap. Those men and women who have dedicated their lives to finding pieces of our past and, more importantly, sharing their finds with the rest of the world desreve greater recognition. those people who decide to steal those pieces of our history purely for the financial gains deserve much harsher punishments.
Heather Bingham, Wolverhampton
I have been a detector for 20 years and really enjoy the thrill of finding something that no one has held for hundreds of years I think the new code makes everything a lot clearer for all concerned it also makes farmers more likely to give consent to use their land.
Pat Tetley, Sheffield
This great another positive step forward in our Great Hobby, its nice to know that archaeologists believe that we are a vital part of their work. After all most of the treasures found in the UK over the last 30 years have been found by responsible detectorists..
Taggy , Winchester