Finally someone with real world experience!!!
You should not expect the NEW Graphs to read at the higher speeds. AND if you can get some readings it will be delayed readings by Yards/Feet due to the speed factor. So a 2' reading on your GRAPH means you could ALREADY be in trouble!!!
The OLD Flashers will read depth at higher speeds. That is why some people are getting the OLD Flashers for the high speed depth readings.

In all this discussion, are we to assume that you have gone thru the menu, and set/changed the settings to allow the graph to read at higher speeds? However, I rely on my flasher, while traveling on plane.

I have an 1197 and it doesn't read at speed. I just put on an older Eagle and run 2 graphs, the Eagle just reads depth pretty much and I put the outer ducer on the inside of my hull. It works for me.

Here is my question. Why do you need to know the depth from behind you at 20+? If you are looking for something idling, it'll read. My graph is on mapping if I'm on plane. You will be dead at a stop before your graph tells you you're to shallow.

P.S. Does it quit reading when you lift your trolling motor? If so change data source to "This Unit"

What he said. The pucks are out of the water.

I still have constant depth readings at 30+. uou shouldn't be losing it until closer to 45 if you have the transducer set up properly

I don't know if this will be any help, but I ran into the same type issue when I installed a HDS unit on my boat. I mounted the puck style shoot thru hull transducer and everything worked great until one day I accidentally changed the frequency on my unit. I got on plane and it started randomly flashing depths and then nothing on the depth. Once I realized the frequency was different and changed it back its been fine since while on plane.

mine reads until I hit 90mph. haha j/k mine stops reading when im say 65=mph because my whole boat is out of the water. If I was to trim down a tad at WOT it would probably read

Very good point. it needs to be on the highest frequency you have...odds are it's 200.

I have a Lowrance transducer mounted flush with the back hull. No thru-hull for me. I don't get readings on pad, but I'm not trying to mark fish while I'm on pad either. I'm going to a spot. Once I'm on that spot, I slow down and idle over the places I'm trying to mark fish, and I have no problems. That's just the way I use my graph personally and it works form me. To each their own...

Josh, what ever came of this? Did you get it figured out?