Pinpointing and digging: field technique that finds more and damages less

Two people with the same detector rarely find the same things. The difference is technique: how they sweep, how they locate a target and how they recover it. This guide covers the habits that make the biggest difference, from the first swing to the filled hole.

Before you start

• Check the settings: ground balance, sensitivity, and a discrimination level you understand. See our guide to ground balance.
• Test on known targets: bury a coin, a nail and a small piece of gold or a ring in a known place, and listen to how each one sounds at different depths.
• Bring the right tools: a pinpointer, a solid digging tool, a finds pouch, a bag for rubbish, water and a charged battery.
• Have permission for the land, and keep away from protected sites. See the law in Morocco.

Sweeping correctly

1. Keep the coil parallel to the ground during the whole swing. Lifting it at the end of the sweep, like a pendulum, loses depth on both sides.
2. Keep it low: about 2 to 3 cm above the ground, without scraping.
3. Sweep slowly and steadily: about one metre per second is a good starting point. Too fast and weak signals are missed.
4. Overlap each sweep by about half the coil width as you step forward, so no strip of ground is left unsearched.

Searching a site methodically

Random wandering covers the same ground twice and misses the rest. Instead:

• Mark a grid with stakes, string or GPS, and search it in parallel lanes.
• Search again at 90 degrees: some targets sound much clearer from a different direction.
• Note your finds on a sketch or in a GPS app. Clusters show where activity took place.

Identifying a good signal

• A good target usually gives a repeatable signal from both directions.
• Iron often gives broken, scratchy or double tones, or a target ID that jumps.
• A signal that disappears when you raise the coil slightly is often a small or shallow object; a signal that stays wide may be a large or deep one.
• When in doubt on mineralised ground, dig: some of the best finds give imperfect signals.

Pinpointing with the detector

The X method

1. Sweep over the target from left to right and note the point of the strongest signal.
2. Turn 90 degrees and sweep again, from front to back.
3. The target lies where the two lines cross.

Pinpoint mode

Most detectors have a pinpoint button that turns the detector into a static mode: the sound becomes louder as the centre of the coil approaches the target. Move the coil slowly in a cross pattern and mark the loudest point with your foot or a tool.

Recovering the target cleanly

1. Cut a neat plug in turf or soft ground, a flap or a circle of about 15 to 20 cm, leaving one side attached so it can be folded back.
2. Place the soil on a mat or cloth beside the hole, so nothing is lost and the site stays clean.
3. Use the pinpointer in the hole and in the removed soil. It saves time and prevents scratching the object with the tool.
4. Check the hole again with the detector after recovery: objects often come in pairs.
5. Refill the hole, replace the plug and press it down. The ground should look untouched.

Handling finds

• Do not clean coins or old objects aggressively: you can destroy their value and their historical information.
• Keep small gold in a sealed tube.
• Declare any object that looks old or historical, as required by law.
• Take all metal junk with you: it leaves the site cleaner for the next search.

Common mistakes

• Sweeping too fast, and lifting the coil at the end of the swing.
• Digging a large hole before pinpointing.
• Forgetting to recheck the hole.
• Changing settings constantly instead of learning one configuration well.
• Leaving holes open, the fastest way to lose access to land.

Summary

Slow, low, overlapping sweeps, a methodical grid, careful pinpointing and clean recovery: these habits find more targets and keep landowners happy. A pinpointer is the single accessory that saves the most time. Browse our pinpointers and detectors, or ask us for advice on your terrain.