Rangerman, That is great info. Next time I'm headed down there I'm going to give you a shout for some help and I'm going to target some walleye. They are such a great fish to catch. I'll be in Red Lake, Ontario June 11-20 fishing for walleye and maybe a few northern. That's where my avatar was taken from. My first "decent" walleye.
As for the SI, its pretty remarkable what you can see with that thing. Much more accurate than the old units. Then again, you have to know what you are looking for. Typically, like when we are crappie fishing, if you know a general location for the fish, say they are holding tight to docks, or suspended inn the tops of trees, you can then eliminate water by searching with the SI. We eliminate docks this way. We'll drive past the end of the dock looking under it with the SI and you can tell without question which ones are loaded up with crappie and which ones aren't.
Thanks again,
Cameron
Hunting & Fishing in Missouri