1. At what depths can a detector find treasure?
It’s impossible to predict with complete certainty how deep a specific detector can be expected to find metal. This is because there are a variety of factors that affect a detector’s performance. For example, the amount of minerals in the soil, the type of metal that’s being detected and the quality of the detector itself impact how deep your detector will hunt. The size and surface area of a target also affects detection. For example, the larger a metal target, the easier and more deeply it can be detected.
Generally speaking, a quality detector equipped with an 8” or 9” searchcoil can be expected to detect:

Small jewelry (e.g., necklaces, thin gold rings) at 3 to 6 inches
Large jewelry (e.g., class ring) at 6 to 12 inches
Small coins (e.g., dime, penny) at 4 to 6 inches
Large coins: (e.g., quarter, silver dollar) at 6 to 12 inches
Mason jar lid at 9 to 16 inches
Coffee can at 1 to 2 feet
Cannonball, helmet, etc. at 2 to 3 feet

Using a searchcoil larger in diameter can also help a detector achieve greater depth. A 12.5” searchcoil produces a more extensive magnetic field that penetrates the ground more deeply to find objects at depths that a smaller size searchcoil can’t reach.

2. How do I pinpoint a target?
Slowly and methodically sweep your searchcoil from side to side, keeping it one to two inches above the surface. Overlap each sweep by advancing the searchcoil by about one quarter to one half of its diameter. Scanning in a straight line helps to keep the searchcoil level and the overlap sweeps uniformly while reducing the likelihood of lifting the searchcoil after each sweep. Listen for a peak in the audio sound. Hold the searchcoil one to two inches off the ground and slowly sweep it back and forth in an X pattern. Note where the sound becomes the loudest. The target should be located in the center of the imaginary X. Many of today’s modern metal detectors are equipped with an electronic pinpoint button. Read your owner’s manual for complete electronic pinpointing instructions.

3. What do I need to know about my detector’s batteries?
NiCads (nickel/cadmium) and nickel metal hydrides are rechargeable batteries that last between 8 and 12 hours and cost up to 10 dollars each. Alkalines are disposable batteries that last between 25 and 30 hours and cost about two dollars each. Because extreme temperatures can drain battery power, it is recommended that you always carry a spare set of batteries. In cold weather, attaching the battery pack to your belt under your jacket can help keep batteries warm and dry.

4. What is discrimination?
Discrimination refers to a metal detector’s ability to reject a target, such as a pull tab and foil or accept a target such as a coin or piece of jewelry based on its metallic composition. With features like Target Imaging and Tone ID, your detector can tell you what your target is before you ever dig.

5. What’s the difference between Coin Depth and True Depth?
Most detectors only offer a basic coin depth reading. Coin depth and true depth are similar to human depth perception. A person’s vision is seriously impaired with the use of only one eye because his field of vision is much smaller with only one eye than it is with two. Coin depth is the equivalent of seeing a target with only one eye. True depth, which can only be found on Garrett’s GTI and GTP detectors, is made possible with additional receivers in a metal detector that offer added depth perception much like having two eyes open.