Title should say Helix 9. Going to upgrade fish finder. I am not very technical , but willing to learn. Helix 9 di si gps Kvd is the one I'm considering,( what the heck is Kvd ?) I've heard they are easier to use than other brands, and that their maps are awesome . Is this the best one for the money? Planning on eventually upgrading to a trolling motor that will link up with fish finder. Is transom transducer that comes with this unit the best choice ? We Fish mostly MS and TN , looks like a lot of options for mapping cards : Lake , Lake+ , Nav., etc ... Which one do you guys prefer ? Thanks in advance !!!