i for one have never used a depth finder on my trips. ive been seriously considering getting one of the smaller units with a display screen for my canoe though. ive been pretty lucky in finding great fish producing spots through the years based off everything MT listed. i can read the shorelines really well and trolling a deep lure tells you a lot also. if my budget allows i might get a depth finder for this years trip.

another really good thing to use, cheaper and more easily used than a depth finder is a pair of polarized fishing glasses. i have a cheap pair from walmart ($5) that work great! it cuts the glare off the water and you can see those submerged reefs pretty well on a sunny day. id say glasses are the 3rd most important thing in fishing. (#1 rod, # lure, #3 glasses)