Thanks everyone, this is an eye opener. Looking to upgrade this boat has been an major "J-curve" for me. ~jklee
Okay, spoke too soon. In looking at depth finders, most are for fishing with big display screen and what I can read on the subject talks about what size thru-hull tranducers you want. So I found the digital (just a number) depth finder and found Uniden QT260 that stated "Adj. In-hull puck" (from Hamilton Marine) and another one from West Marine "DF1000D Hawkeye" a glued in-hull transducer. I am guessing this is what everyone is talking about? I hope I am not too confusing here.