Garrett AT Gold Settings by Site Type: Goldfields, Relics, Parks and Water

Sensitivity is expressed as a share of the range, because the right figure is whatever the ground carries without constant falsing. In prospecting soil that ceiling is often much lower than owners expect.

Garrett gives the AT Gold manual and automatic ground balance and a ground balance window, which lets the machine accept a small band of ground readings as neutral instead of one exact point. In variable ground that is the difference between a usable threshold and constant falsing. Widen the window when the soil varies and hot rocks are sounding off. Narrow it when the ground is uniform and you want maximum sensitivity to faint targets.

Balance on the ground you are about to hunt, not on the track you walked in on, and rebalance whenever the soil visibly changes, after rain and whenever the threshold starts to wobble. The effect of all this on what the screen reports is covered on the AT Gold target ID chart, where the headline is that a poorly balanced machine produces numbers you should not act on.

All Metal, almost always. Small gold is a weak low conductive signal and any discrimination scheme risks silencing it along with the iron. Garrett describes True All Metal as providing the greatest depth and sensitivity for all metal types, and for prospecting that is exactly what you want, with the threshold hum as your instrument: a small nugget usually announces itself as a brief break or lift in that hum rather than as a confident tone.

The cost is that you dig everything, including boot tacks, birdshot and wire. That is the job. Where discrimination earns its place is on relic sites and in parks, where you already know most of what is under the coil is rubbish and you are choosing which rubbish to skip. The Iron Audio settings chart covers that decision in detail.

Dry sand is fine. Wet salt sand is the machine's worst ground, worse than for an Garrett AT Pro, because the higher frequency is more sensitive to the conductive salt signal. You can work it by cutting sensitivity to the point where the machine is stable, ground balancing manually and often, and accepting the lost depth, but nothing about 18 kHz makes this easier.

Fresh water is a different story and the AT Gold handles creeks and rivers well within its 10 foot rating. Use the wired Garrett Submersible Headphones headphones once the coil goes under, keep the headphone port cap secured when no headphones are fitted, and read the AT series waterproof ratings before you wade anywhere serious. For salt work specifically, machines with a salt mode such as the Garrett ACE Apex or the Garrett Vortex VX9 are the honest recommendation.

A pinpointer, first. Recovering a sub gram target from a pile of dug soil without one is miserable, and the Garrett Pro-Pointer AT is submersible to 20 feet with a moulded ruler for recording depth. Second, a pouch that separates finds from trash, because a day of All Metal produces a great deal of the latter. Third, spare power: the Spare AA Battery Holder for Garrett Detectors turns a battery change into a two second swap rather than a fiddle in the cold, and runtime figures across the line are on the battery life and specs page.

What does not matter is another coil, until you have learned the ground balance. Most AT Gold disappointment is a balancing problem wearing a coil-shaped disguise. If you are building out the rest of the kit, the expert setup lists what survives a full season of this kind of hunting.