Bass Fishing Forum - Westernbass.com

My HDS 8 digital depth reading shows anywhere from 2.5 feet to 4.7 feet when traveling at high speed, 40+, and when fishing. The graph shows correct depth when fishing but spotty when running. It will correct itself at times but very frustrating.

The reason for the shallow readings when on plane is because the transducer lost the bottom lock. This can happen because of air bubbles getting between the transducer and the water or the transducer loosing clean contact with the water altogether.

Check your transducer location, angle or attitude to the bottom when on plane. You need good contact with the water without any air bubbles going under the ducer.

I have had the units for almost 2 years and this is the first problem I have had. I now know it is a transducer problem after switching units and showing the same problem. Why would it loose the bottom lock now? I fish Clear Lake and curious if the amount of grass has anything to do with it?

If you are running up North in 3 to 8 feet of water, then the grass will confuse the depth reading to the point it will flash until it regains a bottom lock. When running at 40+ as described, any quick fluctuation in the bottom depth can cause the unit to loose bottom lock. At these speeds you can outrun the return signal from the ducer. The sure to have all HDS units set to Shallow water in the Fishing Mode setting on your sonar menu. This will help the unit maintain a bottom lock.

I had this problem. Lowrance told me to make sure the hds 8 is set on it's own source. Same for the 10. Problem solved.

When both units are on I leave the one not being used on Stand-by so the unit is on its own source.

Units are set in the shallow water mode. Lowrance is sending a new transducer which creates a whole new dilemma of how to remove the 2 old transducers. Gone fishin marine never removed the old one when they installed the new unit,