Hb 998 gps question

Im having a problem with my hub 998 and great plains lake master map chip. I just got back from a fishing trip in which I took out my normal great planes map chip for the southeast states. I had no problems using the southeast map chip. I got home today and swapped the southeast for the Great Plains map chip and headed down to my local lake. When I got on the water I noticed that some of my way points are out of water according to the gps when I know thats not true. I have adjusted my water level offset so the contour line readings match actual depth. There is still waypoints that are out of water. Does anyone have a idea what this problem could be?

thanks

I've seen this issue when the Track data hadn't been cleared in a while ...

*Press Menu 1 time while viewing the Chart view ...
*Cursor down to Clear Track ...

You might also Restore Defaults under the setup tab ...

Rickie