Boat control?

Two fold question, we were out in a 17 ft Crestliner that we did well on, but we had a few boat control issues...one the speed one the GPS jumped around quite a bit and when we had to net a fish the front end of the boat would start going way off course...would larger trolling bags help with this problem? Or is it normal for speeds to jump some? GPS is a lowrance elite 4.

Thanks !
Ben

I had this problem last year. I was using 1 bag straight out the back. I went to 2 large(48") bags. One on each side. And used more throttle.
I do still get the speed jump on the GPS. I have the Elite 5 so it's a similar model. In choppy waters I do my best to average and take the speed it's closer to more of the time. With te new bag setup and less that 3 ft waves I can usually keep the speed from jumping more than .3mph.

Ok I kinda figure with waves and current it would jump some! Thanks for the response!

Ben