Thanks to all.  Good advice!  This thing about attaching the transducer so it shoots through the hull is foreign to me.  I've obviously got some research to do.  I'll have to stop in to "Northwest Canoe" in St. Paul and see if Dennis can show me.

But thanks to all of you, at least have some leads to pursue. 

Honestly, I will say I was convinced to bring along a depthfinder after reading the entire recent thread on "walleye advice."  Excellent information.  I've always just trolled crankbait.  Managed to catch walleye, especially by stopping and focusing on places where I catch the first one, but the depthfinder seems to be the common ingredient to consistently successful walleye fishing.  So thanks, doubly, for all the good advice.