I've been doing a little research on fish finders and thought you might be able to help me out with a few questions. After doing some preliminary research I'm leaning toward a Garmin 160 Blue or a Garmin 240 Blue. I understand the "Blue" models have dual frequencies, which help in picking up what's below. Is this correct? My second question has to do with resolution differences between the 160 and 240. Although I'm sure I'll notice the difference between the two, will it be noticeable enough to make a significant difference in seeing bottom contour, identifying bottom makeup, identifying bait and spotting fish. Thanks for any thoughts that you (or anyone else) might have.
JMS