When coinshooting or searching for jewellery in most parks or schools, it is probably best to avoid schlepping a shovel (of any size) around with you. Seeing a digging implement, many observers will suspect the worst; some may even notify authorities. Over time, such encounters may lead to more areas being closed to the hobby.
The good news is that with practice, you can become proficient with coin ‘popping’ methods like the one shown below. This leaves no plug behind to turn brown or betray your visit. These ‘Recommended Recovery Methods’ come from Bob Sickler at Tesoro Metal Detectors (http://www.tesoro.com/info/faq/recovery/).
METHOD 1: “PROBE AND DRIVER”
Used in less moist lawns where targets are not so deep (one to four inches) and the “Plugging” method is objectionable. The Probe and Driver method requires more practice but is much less damaging to grass than Method 2. The probe used can be a non-metallic probe such as a modified fiberglass fishing rod or a metallic probe such as a blunted ice pick. A non-metallic probe will be the least damaging to the target. After pinpointing target, use the probe to locate target depth (Fig. 1A). Next, insert eight-inch screwdriver on center just above target and rotate slightly to open ground (Fig. 1B). Now insert screwdriver just under target at an angle and lever target to surface (Fig. 1C). Brush all loose dirt back in the hole and close by exerting pressure all around opening (Fig. 1D).
METHOD 2: “PLUGGING”
Used only where allowed in natural wooded areas and very moist lawn areas. Plugging in hard dry ground can damage grass roots, leaving yellow “dead spots” in time. After pinpointing target, cut three sides of a four-inch cube around target center (Fig. 2A) using a six-inch sturdy hunting knife. Cutting a “hinged” cube rather than a cone shaped plug will properly orient its return, prevent removal by a lawnmower, and lessen the chance of scratching the target. With the knife blade, carefully pry against the cube side opposite the “hinge” (uncut side) and fold back (Fig. 2B). Scan searchcoil over plug and hole to isolate target location. If target is in plug, carefully probe until located. If target is in hole and not visible, probe bottom and sides until located and remove (Fig. 2C). Repeat scan for additional targets. Replace all loose dirt with plug. Seat plug firmly with foot (Fig. 2D).
And here’s some additional advice from wpaxt over at the Friendly Metal Detecting Forum:
You will need to practice. A test garden/patch is helpful. Once you know the sweet spot of the coil you are using & can approximate depth (either thru a meter or tone) it can be done rather easily. Obviously if the coin is deep then a plug is the way to go. A trick to use with really shallow coins (3″ or less) is to scrub the point of your pinpointer over the ground. You should be dead center when the probe sounds off. Last thing, be aware that an ice pick, if applied with too much pressure, will scratch a coin. I prefer a brass probe, but you still have to be careful.