The Garrett AT Gold was released in 2011 and is still in production. It is a variation of the excellent Garrett AT Pro metal detector, but modified slightly to make it a better detector for prospecting. Garrett really raised the bar in the detecting world with the AT models. These detectors are waterproof to ten feet yet give up none of the features one would normally expect in an above water detector. They even have an external speaker for use above water which can be submerged without harm. Best of all you pay no penalty in either weight or price. The Garrett AT models provide exceptional value in metal detecting.
The AT Pro is a 15 kHz detector that features full notch discrimination. The lower frequency means that it can be used in salt water. It also allows for custom discrimination, such as tuning out coins to concentrate on likely jewelry targets. The AT Pro lacks a true threshold based all metal mode and so is less suitable for nugget detecting, although it can and will find gold nuggets.
The AT Gold runs at a slightly hotter 18 kHz and has a true threshold based all metal mode. This makes it a better nugget detector than the AT Pro. However, it is too hot to run on wet salt sand or in salt water. It also has only a couple preset discrimination patterns and so lacks the custom discrimination ability the the AT Pro has.
The AT Pro and AT Gold both have three search modes. The first is a discrimination mode preset to accept all items with an audio beep in different tones and a visual target id. Pretty much everything goes beep, but you can adjust the level at which iron/steel is rejected completely, and this is saved when the detector shuts off. The mode is preset and only the iron rejection level may be modified.
The second mode is a preset discrimination mode with light foil and pull tabs set to audibly ignored. A so-called coin pattern that eliminates common trash but beep on common coins. Again, only the iron rejection level may be set and saved. The rest of the pattern is preset and cannot be adjusted.
The AT Pro has a third discrimination mode, a fully adjustable notch mode. Notch refers to the ability to set certain non-ferrous items to be accepted or rejected in ranges or "bins". The non-ferrous discrimination range is split up into sections or "notches". For example, all foil items may fall into a range of 0-20 on a scale of 0-99 and so would be said to fall in the 0-20 section/range/notch/bin. That 0-99 range can be split up into several notches and this varies by model. On the AT units you get 12 non-ferrous notches.
Garrett AT Gold with 5" "sniper coil"
An independent adjustable notch system lets you decide what sections get accepted and what get rejected. For instance, you could decide you are looking for something that reads like a nickel and set only the nickel range to beep, all other ranges get ignored. All nickels and items that read like nickels would go beep, and that is it. Or, you can set all non-ferrous items EXCEPT the nickel range to go beep, and ignore the nickel range. The AT Pro in the third search mode allows you to create a custom notch program and save it.
Again, both units treat ferrous items the same. You can adjust how the ferrous targets respond and save the setting. It is only in how non-ferrous targets are treated that the units differ.
The third search mode on the AT Gold is a pure unfiltered all metal mode. All items are detected, with significantly more depth. The all metal mode has an adjustable "iron audio" feature that will identify strong ferrous targets with a low or broken tone. The all metal mode also features a unique ground balance "window" that can expand beyond the normal area spanned by a ground balance control in order to eliminate some types of hot rocks.
Gold nuggets found with Garrett AT Gold
So on the AT Pro the third mode is an adjustable notch discrimination mode, on the AT Gold it is an unfiltered all metal mode. Finally, the AT Pro comes with an 8.5" x 11" DD coil whereas the AT Gold comes with a smaller 5" x 8" DD coil.
I think the Garrett AT Gold is an exceptional detector and for anyone wanting to use a VLF detector in and around water it is an obvious choice. Do note that while the detector itself is submersible the headphones that come with it are not. To actually use the unit face in water with mask and snorkel requires optional fully submersible headphones.
The depth of detection, sensitivity, and ground handling are on par with other 18 kHz nugget detectors. However, if the waterproof feature is never going to be needed (desert detecting?) then the special lubricated O-ring connectors for the headphones and coils add service issues that can be avoided with a normal dry land model. Therefore I think the decision to get a Garrett AT Gold depends in large part on whether the waterproof design is actually needed or not.
|Technology||Induction Balance (IB)|
|Transmit Frequency||18 kHz|
|Autotune Mode(s)||Pre-Set Slow Motion|
|Ground Rejection||Ground Grab, Manual|
|Discrimination||Adjustable Plus Presets, Visual ID, Tone ID|
|Audio Output||Speaker & Supplied Headphones*|
|Standard Coil(s)||5" x 8" DD|
|Optional Search Coils||Four accessory coils available|
|Operating Time||20 - 40 hours|
|Additional Technology||Ground Balance Window|
|Notes||*Uses special waterproof connection for headphones, adapter needed to use other brand headphones|
*Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.