The Garmin has GPS and is able to mark waypoints. Is that what your talking about? What else can the helix mapping do besides that?
Here is part of the description: "the Humminbird HELIX 7 SI GPS has the punch to deliver crystal-clear SwitchFire® Sonar images, provide Side Imaging and Down Imaging scans loaded with incredible detail, manage up to 2500 waypoints/45 routes, and support LakeMaster®, AutoChart®, AutoChart Pro, and Navionics® Gold/HotMaps mapping programs via its single Micro SD card slot. Includes internal precision GPS and built-in UniMap map. - See more at: http://www.basspro.com/Humminbird-HELIX-7-SI-GPS-Fishfinder-and-Chartplotter/product/1506251146/#sthash.7M8FB1hC.dpuf
What is Lakemaster, autochart, navionics, etc? Is it worth the extra $200 to have these options? I assume I would need to purchase an SD card.
Thanks again, you have been very helpful