No such thing as too much time in a canoe…as long as you’re not trying to compete with the big boats where you’ll get a lot of this…
Piranha Fish finders are relatively cheap and work well, if you’re just looking for a product recommendation.
You plan on using the finder only when you are running your trolling motor? Or will you use it in situations where you will not have a 12-volt battery to run off of?
You can go one of three ways for the main unit. You can buy a regular depthfinder which runs off a 12-volt battery and run it as designed, or you can convert a regular depthfinder to run off of 8 AA batteries, or you can buy a portable unit which generally runs off of lantern batteries or 8 smaller batteries.
Then for the ‘ducer you can use a suction cup mount, a trolling motor mount, or shoot thru the hull. Depending on what material your canoe is made from, even ‘ducers designed for suction cup or trolling motor mounting can shoot thru the hull. This works well with kevlar or royalex in most cases but I’ve never tried it thru aluminum. Couple ways to rig this, either temporarly or permanent.
The best option to use will really depend on where you plan to use your fishfinder and what features are most important to you. I played around with using speed/temp before and decided that in a canoe they are pretty pointless.
Feel free to PM me if you’d rather…