I installed a Garmin 740S this summer. I'm loving the system, it's really fast. The Radar overlay is great too. The only problem I am having is that some of the depth numbers on the maps are not accurate. There are some spots that it says one depth (140 feet for example), but we get there and it's more like 280 feet. I have found more than one area like this, and I'm wondering if anyone else has had this same experience.