Once your HDS unity is set up they preform great, all are dual freQ, just make sure to get the 83-200 transducer, other things that affect sonar clarity are interference and surface clarity settings, both should be set to at least low to medium, next set to freshwater use, turn off the amplitude scope, also make sure your unit has the latest upgrades there have been 3 in the past 6 months,currently 4.1 for gen 1s and 1.1 for gen 2s..... i can make a dock call if you need help...Ed