Went to the lake today trying out new Elite 7 HDI. I had more problems with GPS than sonar.Having problems with trails and routs and the differences. I am trying to read the manual and learn how to get benefit from GPS. Lost depth today, cut off unit and back on and had no more problem. Did i have a setting off ?. I am amazed at what this thing will do (WAY MORE THAN I HAVE THE KNOWLEDGE TO MAKE IT DO). Other than the manual is there any good web sites to help explain GPS. I am not going to give up!!!!! Thanks