I don't have any pics but I think there are some in the inuk photo gallery.  There's 2 ways - one is less intrusive but more cumbersome and second is relatively permanent.

Method 1 is simply placing the transducer in a small dish of water sitting on the bottom of the canoe.  Make sure there is also standing water inside the bottom of the canoe.

Method 2 is using silicone to adhere the transducer to the bottom of the canoe - usually behind the stern seat.  Honestly, I tried doing it through the top of the stern plate but it performed poorly through the foam filling inside the hull.

We use method 2 along with the suction cup.  Yes,we bring 2 transducers.   ::)

Keep in mind that you will not get the water temperature reading this way.