So much depends on the soil, ground balancing, size of the object, recovery speed, etc. While the EQ can perform pretty well on say, a nickel, per example, there are machines out there that can eat its lunch in terms of depth, the Sov Series being one of those machines. But in these cases you're not really relying on a traditional target return, but rather certain types of disruptions in the threshold. The problem here, of course, is that you could just as easily be chasing a large pull tab at 15-16 inchers, or more....lol
My lakes and typical hunting areas are pretty forgiving soils so I run my EQ 800 mostly in the gold mode with slower recovery speeds so I can also utilize this mode's true threshold which also adds additional inches to my efforts.