I bought one that is OK. It fits onto the center thwart via a set of rod holders (fishing) and a 2-3 ft PVC tube, and so is adjustable for angle. They can be pulled up for distance paddling, then lowered for use. I Like the design but not so much the materials. You can make a set that are stronger. I will post pix later. I also think the float or pontoon portions need to be more substantial than these are. I will be working on fixing that in the next week or so.
These are best used during the day I think, although having a couple 50w LED lights on the front and side of the canoe might be nice. Fed by a battery in the center of the craft, it could add to stability. Keep the lights on your shooting side, so you aren't tempted to keep turning to both sides.
ChuckC