I posted the same question to the board ~ year ago. Most recommended the Lowrance ifinder H20, which I purchased. Also purchased the (sp? novonics?) map chip which gives me KY, Tn, ....., lakes. Been very happy with the unit. Have no experience with the Garmin units, nor their maps. Question for Green River Time? If one compares the two maps side by side, what would be the pros and cons?