I have also seen this with my Raytheon color sonar. Think big balls of
fish and bootom far away?

Cheers MC

Mike wrote:
Been pondering for awhile how to upgrade the electronics on the boat. I
guess they were state of the art in 1979 (loran, ancient GPS, Raytheon R10X
radar, etc) but the radar is broken, loran is kind of an old joke, and the
GPS probably has wooden components. The radar needs a new magnetron tube
that would cost over $600 just for the part, so that's out of the question.
The old depthsounder gives good readings in shallow water, but tends to go
crazy in deep water, sometimes showing very shallow depths for no particular
reason. I was thinking I had a submarine 20' under me quite often on the
trip up Baja!
Was leaning a little towards the whiz-bang mapping GPS with radar overlay
technology, but after reading about split screen mapping GPS/sonar units in
Practical Sailor, I'm now thinking of going that route with a stand-alone
radar. I really like the idea of seeing bottom contours next to the "you
are here" GPS display right at the helm. Any thoughts? What would you do,
and why?
Mike