Just got back from Marine Repair Center here in Springfield. Took the boat over to get an appointment to replace the 2 trolling motor batteries and the starting battery. I have Interstate Batteries in the boat now, that is what come with the boat new. I was told by Marine Repair Center that if I have been having interference on my fish finders it might because of my Interstate Starting Battery. It seems that they have found that Interstate batteries now have lower voltage than other brands! Just talked with my next door neighbor who works for U-Haul and he said that in the past year Interstate Batteries have moved their production to Mexico. And U-Haul has had a lot of problems with them having low voltage. He said that the Springfield office won't purchase Interstate batteries as a replacement battery anymore.

For me I am going with the Exide batteries that Marine Repair Center carry. #1 I am not a Kyle Busch fan anyway!

I don't know if there is anything to the above information but it seems funny that I got the same story from 2 different people in about 30 minutes today! So if your having interference with your fish finders you might check for low voltage!