The effective range will have to be determined when people get more extensive use on-the-water with them. Most brands when expressing range are referring to how far it will pick up the bottom rather than how far it can clearly show your lure or a fish which is my interpretation of range. I'm disappointed in Garmin for going out of their way to keep the technical aspects secret. It's not like we won't find out. It makes me suspicious that the hype is outpacing the actual capabilities of the unit. This was especially true for Lowrance SpotlightScan and Humminbird's 360. Kind of like politics. A speck of truth and a lot of hype goes a long way. Apparently there are at least some specific situations where the hype meets reality. With the full specifications we could reasonably predict both the range and limitations of its application. Right now, they don't want us to be able to do that. The hype encourages our imagination to expand the range beyond its capability. Their refusal to release the technical info is clearly to hide its limitations. For some of us that will limit sales rather than promote them. I told the Garmin engineer at BM Classic that I never buy these units based on promotional literature but only after carefully examining it technical specs. It's quite difficult for a unit to perform beyond its technical specifications.