can anyone help me understand how to use the grayline feature to distinguish hard to soft bottom, i use a bottomline 210 and a pinpoint 7800. thanks
If you are going to use gray line to distinguish between bottom content and type, you must turn off the automatic gain. If the automatic gain is left turned on -- the unit will basically move the gain up and down to keep the gray line constant.
If you have the automatic gain turned off, and the manual gain turned high enough to see a nice second bottom, if the range is turned up hight enough -- then the thickness of the gray line will change, when the bottom type changes - when going from soft to hard, and vise versa.
Basically, soft bottom will absorb the signal and reflect little back. Thus you will get a very thin gray line.
If you have a hard bottom, you get a very good signal reflection, and thus you will get a very thick bottom signal.
Take care
REW