The Difficult Ground Type setting is the default setting and is recommended, as gold is usually found in areas with highly mineralised soils.

The Normal Ground Type setting will provide the greatest detection depth but can only be used in quiet soils where there are lower levels of mineralisation.
If the detector is unstable or noisy when using the Normal Ground Type, you should switch to Difficult.

The Severe Ground Type will provide the lowest detection depth and should only be used when detecting in areas with extremely high levels of mineralisation, or when you need to raise the coil above the ground when using the Difficult Ground Type.