When you get out on the lake at dawn and the screen goes almost totally red, is it smelt? Shrimp? Perch fry?
I could barely use my flasher or sonar for a while Saturday morning on Lake George, NY. (Even with the gain turned way down on both units.)
I going to look for some kind of seine or net I can drop down and quickly pull back up so I can see just what it is that's going by.
Ive seen that on George, only seems to be in the weeee early morning or when its dark.
Not sure 100% but I noticed little fish swimming in my hole when my light is on for my pullover. Maybe an inch or 2, almost transparent from the dorsal back.
Try to put a light down pointing at your hole and wait a few minutes, you will see them maybe an inch under the water just chilling there, I used my dip next to snag one to check it out, never used it for bait though.
They go away shortly after sun up for me.