I get the feeling many
times one of the best
things about the
Humminbird side scans
is being over looked. It's
being used as a one
point tool.
The screen capture
next to here shows a
weed point.  I think a lot of people look at it,try memorizing it,  
then keep on going not thinking of this as a tool.  With the
screen capture off, I freeze the image and move the way point
mark along edge of the weed line and mark way points ever
so often, like the X's in the image. Now on your chart plotter  
you have a series of way points out lining the weeds.  All you
have to do now is watch the plotter and move along out side
those way points and cast the line.
Now if your using a moving map software like Fugawi, you can
import the way points and with the track library open you can
drag the way points in to it creating a track around that weed
point that will show up nicely on the chart plotter.
Here's an example I did on
Green Lake in Chisago
county.  I knew there was a
hump from when I did my
first survey for a contour
map several years ago.  
But I didn't know the exact
out line or that there was
some thing leading off it to
the SW.  I'M still not sure
what it is, it looks like a
road. The lake was
extremely down in late
1930's, you can check it
out in Local Lakes Imagery
, but I don't think it was
ever that low.
When all was said and done here's what the out line I created
looked like on my Green Lake contour map in Fugawi. The lime
green line is the track I made out of way points I marked along
the edges you see in the images above.
Don't think I'm not going to be fishing that this winter.  Always
think beyond the one way point.
Using the Humminbird side scans as a tool