DFF3d

[buco]

greetings, I have a FURUNO DFF3D with Tztouch3 16",
I wonder if the probe can replace a reef with a dense shoal of fish
A rock with a fish is obvious to me, and later I can't find the rock.
I have a plotter.
Please help.

 

[FishTech]

Yes, I do believe that if you go over a dense enough shoal of fish the your DFF3D could mistake it for a reef or rock. Especially if as you say, you cannot find the reef or rock upon your return to the area.
You could try lowering you gain setting and it may better differentiate between fish shoals and bottom structure.