Standing in a farmers’ field and ankle deep in mud, Colin Toddy Irvine often witnesses the sheer delight that comes with rubbing centuries of muck away to reveal the first glimpse of a battered silver coin.

“It’s the joy of finding something,” he says. “I’ve seen businessmen who have lots of money find a coin that’s only worth around £10 and they’ll be jumping up and down with excitement.”

Beneath his feet, waiting to be sprung free from centuries spent smothered in mud and soil lie coins dropped by passing Roman foot soldiers or medieval horsemen, once shiny silver buckles and glittering buttons, ornate brooches which held scarves in places or adorned coats, and all manner of someone’s once prized metal bits and pieces.

Autumn is prime time for metal detector enthusiasts to descend on farmers’ ploughed fields in search of a glittering prize. This year is expected to see their numbers boosted further by a new wave of enthusiasts driven outdoors by the pandemic and in search of new safe and socially distanced hobbies.

According to the National Council for Metal Detecting, this year, as in previous years, has seen a gradual increase in membership.

While the flow of objects reaching the Treasure Trove unit base at the National Museums of Scotland in Edinburgh recently led to it advertising for an additional Treasure Trove Officer to expand its work.

Most of the 2,500 or so objects it handles each year are found by amateur metal detectorists. However, this year there has also been a steady flow of ‘lockdown’ items found by homeowners pottering in their gardens or spotted by walkers or beachcombers.

According to Mr Irvine, a drop in the price of top quality metal detectors – a waterproof, Bluetooth model which a few years ago might have cost £1000 is now a much more accessible £300 or so – is also fuelling a rise in numbers taking up the hobby.

What were once monthly events had grown to weekly outings attracting up to 100 people prior to lockdown, he adds.

“It’s the best kind of socially distanced hobby,” says Mr Irvine, who sells equipment and provides training through his Denny-based business Metal Detecting Scotland. “People can disappear when there’s 100 acres of land to cover and communicate by radio.”

At one event which he ran earlier this year at a farmer’s field near Falkirk, enthusiast Gordon Anderson bent down to lift a mud-caked object from the ground. As his fingers stroked away generations of dirt, he realised he was holding a Bronze Age axe.

“It is 3,500 years old but as good as the day it was made,” says Mr Irvine, who picked up a metal detector 30 years ago and became hooked on the buzz that comes from finding something then trying to decipher just what it might be.

That Bronze Age axe encapsulates what he loves about metal detecting: “It gives you shivers when you find something like that,” he says. “The guy who found that axe is the first guy to hold it in his hand for 3500 years.”

Most outings turn up something of interest, whether it’s coins, broken buckles or jewellery. “We are saving these items from getting damaged by farmer’s ploughs,” he adds.

Once inspected by the Treasure Trove unit, many items are returned to the finder. A handful, such as a beautifully crafted silver crucifix found by Graeme Cook in a field near Dunkeld, can end up in a museum.

“I was thinking it was over for the day,” recalls Mr Cook. “I went over a piece of land that ten or 15 guys had already gone over. I was lucky.”

He dug out a sod of earth, brushed off the soil and washed what was left away in a puddle to uncover a 2.5ins long solid silver crucifix with Christ on one side, Madonna and child on the other.

Thought to be up to 800 years old, it is now in the hands of Treasure Trove.

As well as cheaper equipment and long days of furlough with nothing else to do, headline-grabbing finds, such as in June when Mariusz Stepien uncovered a hoard of Bronze Age artefacts in a field near Peebles, are also said to be luring more people to try their luck.

However, it’s not all Bronze Age axes and medieval brooches. Alastair Hacket, president of the National Council for Metal Detecting, cautions newcomers to lower their expectations and focus on the potential health benefits of the hobby instead.

“The NCMD has had many attestations of the benefits from individuals who have been suffering stress, anxiety, and in some cases, post-traumatic stress disorder,” he says.

“I explain to people thinking of taking up the hobby that over 99% of what they find will be scrap metal - bits of iron, lead, bottle tops, ring pulls, etc.

“You need patience, and you need to abide by Scotland's Treasure Trove law and the detecting code of conduct that the NCMD expects all members to follow.

“The fact is that you have a statistically better chance of scooping the jackpot in the national lottery than you have of finding treasure.”

Some do strike lucky. In 2009, novice metal detectorist David Booth was using a basic model metal detector when he found a collection of Celtic torcs, or neck ornaments, dating from 300 to 1000 BC, at a site near Blair Drummond Safari Park.

And Derek McLennan earned a £2 million finder’s fee after uncovering the Galloway Hoard of Viking-era silver, sparking a Court of Session dispute with landowners the Church of Scotland, which claimed entitlement to a share.

However, the rise in interest has raised concerns that not all finders are aware of, or choosing to follow, strict rules surrounding metal detecting and the legal obligation to report finds of archaeological significance to the Treasure Trove unit.

“I follow a few Facebook pages and it’s amazing the number of people who think they can wander around the local park, digging holes,” adds Mr Cook. “I reply to a few posts saying ‘make sure you get permission first’, but people think I’m being a stick in the mud trying to stop them enjoying themselves.”

In England, illegal metal detectorists have become an increasing problem with historic sites including Hadrian’s Wall and Old Sarum in Dorset targeted under cover of darkness.

Although such ‘nighthawking’ practices are extremely rare in Scotland, parts of the Antonine Wall have been targeted in the past. While there are some concerns that some items found by new hobbyists or by accident be going unrecorded because finders don’t understand the rules.

“Metal detectorists are part of a community that are aware of the Treasure Trove,” says Emily Freeman, Treasure Trove Manager. “But if someone is new to the hobby, they might not know they should be following rules and regulations.

“The (metal detector) clubs are not happening because of Covid-19 and we have not been able to do our usual outreach events at museums where we would meet new detectorists.

“There is a danger that quite a lot could slip through the cracks.”

Meanwhile, Alistair McCabe has found coins and artefacts dating from the 12th century onwards, axeheads from the Bronze Age, brooches and other personal effects from the Iron Age since he began metal detecting in 1986.

Many, including two flanged axeheads from 1900BC were found in his local Sidlaw hills.

“Education on the legal requirements regarding the finding of historic objects should be considered a top priority to anyone thinking of taking up the hobby,” he says.

“There is absolutely no doubt about it, metal detecting has changed my life, and through some of the finds history has been rewritten.

“This is the potential that lies within this amazing hobby.”