does it have an ice ducer or a skimmer type ducer for in the boat? I have 2 garmin 93sv units on my bass boat and if they are on the same frequency they will cross talk in deeper water even though the ducers are nearly 19 ft apart. I would try to figure out the cone angle of the ducer to estimate it's coverage and if it only has one frequency setting then you may be at the mercy of others nearby on that same frequency. If not fishing in a large group of close people, other than you and your guest then you should be able to change your vex's frequency with the interference button and that may clear it up on the garmin.
