The "Medway History Finders" say they had to trash an archaeological feature containing seventh century personal ornaments "because of where the find was made very close to the main road we had to dig the hole to stop nighthawks robbing the place". What nighthawks? Why the nighthawks on the road, you see.
What is the risk? Let us imagine (for the sake of argument) that a car goes past the site on the A20 once every three seconds. When did the club dig start and finish on 16th February? We don't know, let's say it started at nine, and finished at six as it gets dark. Nine hours. That would be something like 10800 cars could have driven past in that time. How many of them contained observant nighthawks? Well, the estimate that there are 10000 metal detectorists in the UK means that one in six thousand people are metal detectorists, a minority in other words. We are continually told that the number of nighthawks is a "small minority' within that metal detecting community. If there were 12000 cars driving past, that means statistically only two other metal detectorists were travelling that road at the time the rally was on. But the trashed grave was only dug in the afternoon. A metal detectorist driving past the gap in the trees through which the cluster of figures on a distant hilltop might be seen might be looking at a given moment to the right of the car, to the left, or the front, or looking at his delightful female travelling companion as she laughs at another of his jolly tekkie jokes. So, what are the chances that the event was seen by a single metal detectorist, let along one of the "few" (we are told) dishonest ones?
We must remember that people driving along the A20 should have their eyes on the road, not gawping at groups of figures on a distant hilltop glimpsed through the trees. A group of people in a field could be bird-watchers, vermin-catchers, botanists, druids. Bombing along the A20 at 60mph, even if you saw some blokes on a distant hilltop and recognised they were metal detectorists, how could you pinpoint that particular spot in the dark afterwards, especially in a hill covered with other patches of disturbed earth? Pretty impossible actually when you think about it.
Even if... What could the metal detectorists do to safeguard the site for the night? They could camp out on the site, take it in turns to spend the night in the field. In their cars if need be. On the Monday a site guard could be hired from a security firm, so it would only be one night. This was the option adopted by the guys that dug up the child's lead coffin a few weeks back
Access to the hole could be blocked. The farmer could be asked to park his tractor in the field overnight with a bit of heavy agricultural machinery over the spot. Failing that, a concerned metal detectorist with a car capable of getting there could drive into the field (it looks quite dry under-wheel) and park his car over the infilled hole (along the slope!). He'd not even have to stay in it. This would draw attention to the spot, but there's not a lot a nighthawk could do about it, metal detecting under a family saloon is somewhat a difficult task even in daylight.
Alternatively they could render finding the spot difficult. They could quickly turn over a few areas of soil in immediately adjacent areas shallowly and scatter some modern non-ferrous objects around in them (the green waste petition tells us that aluminium foil and can sherds are a nuisance), a nighthawk would spend a few hours trying to find the 'right' hole in the dark.
I am sure there are in fact several dozen things artefact hunters could do to render the findspot secure from illicit tampering. Surely a mastery of the armoury of methods is part of responsible metal detecting. Trashing a site by hoiking everything out is neither best practice nor responsible detecting. Search agreements should contain such a clause referring to this necessity to avoid loss of valuable finds and information, and both parties (landowner and searcher) should declare readiness to engage in (and tolerate) such action as may be necessary to protect a find left in situ.
Indeed, why have the PAS and Treasure Unit (perhaps together with the Scottish Treasure Trove people) not issued guidelines about this already? How may Treasures have been dug out by metal detectorists infected with the Gold Rush and enjoying themselves immensely at the expense of the archaeological record, weakly justifying themselves by painting a "what if" image of rampaging nighthawks just poised to grab what they leave behind?
Vignette: Safeguarding findspot from overnight interference, not rocket science.