View Full Version : Lowrance reading incorrectly

08-25-2009, 08:41 AM
I have two Lowrance units, LMS-480 and X67c, that both go haywire in shallow weeds. By this I mean when the water get to the 4 ft range the units work for a bit then read in the 100's of feet. The strange thing is the bottom reading is still visible at the correct depth but the big number in the corner is showing 100s of feet deep (the scrolling screen seems accurate). Is there a setting of something else I can do to keep this from happening?


08-25-2009, 09:00 AM
This is one reason I hate these units. I still use a Zercom flasher and its never lets me down. Maybe your unit has a flasher mode on there?
I was with a guide last week and his unit would loose a lock on bottom depth when he would get into heavy weeds all day long. Get use to it it happens to every Lowrance unit I ever seen.

08-25-2009, 09:01 AM
Was having the same problem (as soon as I hit shallow weeds I started gettings readings of hundreds of feet) with my Humminbird Matrix 27, and found that I had set the "60 degree cone" sensitivity wrong. (I hadn't noticed that the settings went both positive and negative from the zero default, and incorrectly assumed that more (plus) must be better.

I had tried reducing the main sensitivity setting... and lots of other adjustments, but that was the one that mattered for me.

08-25-2009, 09:35 AM
I have a 334c. I have the opposite problem, mine looses the bottom when i get into deeper water 15-50'. This is driving me nuts. :(

08-25-2009, 09:42 AM
I am going to try soft booting it. What are the keys that you press to do this? i forgot.

08-25-2009, 09:50 AM
Make sure you have the absolute latest download fix from the company uploaded into your unit--I now have left behind the "shallow depth monster" and am operating just fine.

08-25-2009, 01:51 PM
save way points
then soft boot with it off
then hold pages button and power button reboots you will have to reset all your settings again
anybody have problems with way points deleting by them selfs I have a memory card and have to redo them seems like every other time I turn it on I did reboot it maybe that will help I will find out this weekend

08-25-2009, 02:54 PM
Thanks sheephead.

08-26-2009, 06:48 AM
If you have both of your depth finders on at the same time one will interfere with the other. I have always had the same problem with Lowrance. I usually just turn off the unit at the consol when I go to the bow. My last boat I used two different brands and that also solved the problem. You can also try setting different ping rates on each of the units. That sometimes helps also.

Semper Fi
Bob Pieske

08-26-2009, 08:43 AM
Thank you for all of the replies. I've got some checking to do and a few things to try out.