I simply asked you to give some Lat/Lon with descriptions so I or others can take a look at your issues and shed some light or help with it. That is NOT too much to ask. I also asked you to contact Navionics with the same information. IF you spent 1/4 of the time working with positive actions to get help as you spend complaining, you might be surprised of how much help you would get.
Personally I can only determine anything credible if I can see the facts. Without that specific information of areas in question, NOTHING is credible and will remain worthless until we have something to see and a place to start working to address the issues. I have the mapping for it but nothing to see and no where to begin.... but willing to take a look with some guidance. I am 100% sure that Navionics would be equally supportive of help with your issues.
Tommy
Prostaff Lowrance/Navico
Prostaff Marine Specialist/Navionics