A little background.

I have never used a fish finder before. Would only be using it on a canoe. Can't afford to spend a bunch of money. Would use it on small lakes (90-150 acres). Don't expect the finder to be able to identify the species and weight of each fish.

I plan to slowly paddle around the small lakes and locate structure and depth changes. Accurately marking fish would be a bonus. Guess I also have ideas about sinking some structure in the future and coming back to fish it later. I have a handheld GPS.

My plan is to put the battery in a toolbox, or dry box, and mount the finder on top of the box. Will carry this to the canoe and put it in front of me.

I'll etiher look for a used unit locally, or buy a new one from Bass Pro.

Looks like most manufacturers make a unit that is less than $100. (Garmin Echo 150, Piranhamax 175, Lowrance X-4 Pro) Would these work for what I want to do?

Is there a significant improvement if you go up to something like a Humminbird 561, or Lowrance Mark X-5 Pro?

I have read that getting a color unit can be a big improvement. For what I want to do, would it hellp that much? You can get a color unit (Lowrance Elite 4X HDI, or PiranhaMax 195C) for less than $200.

The DSI images I see are pretty incredible. The Lowrance Elite 4X HDI with DSI looks pretty iimpressive for this newbie. Color, dual imaging, and track back for $200.

Probably $200 is my max limit. Would the $200 unit be that much improvement over the $100 unit, or should I just use that extra $100 to buy a trolling motor?

Sorry for the long post and all the questions.

Trevor