Topic: Change in scanning color???

[basszilla]

Question:  Why does my unit change to a darker color by itself without moving settings.  In the pics I am at 24 feet were the road bed is.  Then the break drops to about 28 feet, but the color of the scanning becomes darker.  The darker scanning continues.  I under stand that the unit does the darker shading to tell the user that there is a change in depth.  I have pictures of scans were I am 30 plus feet with breaks and the unit will not have the change of color.  This has also happen during shallow scanning.  Any suggestions???  Thanks in advance...

[calli1]

From what I am seeing is the change in contour of the bottom of the lake.  If the bottom colors get brighter all of a sudden then that means a possible harder bottom as well as a humpr or shallower waters.  When the colors fade to lighter...then I would say a gradual decline in the bottom where the water is getting deeper.  When this happen the beam can't scan the bottom as well but on a sudden rise in the scan zone...the bottom will appear a much brighter color. 

[lcookie]

Most likely it is due to a change in bottom hardness since your depth did not change that much.  Soft bottom equals darker returns.

[Humminbird_Greg]

When the color of the Si sonar returns turn darker; it is an indication that whatever the bottom of the lake/river is made of, it reflects less sonar energy back to the transducer.  This normally means a software material (say from rock to mud) but it could also mean that the surface of the bottom is angled away from the transducer.

[sonar2000]

HB has a good write up on sonar returns in the book or disk. It is also available in the web site.
It explains the returns real well..

Chuck