I've noticed one area of my local lake, which is a major lake, largest man-made in NC, has incomplete topo mapping. One area that I like to fish a good bit has no topo. Mapped all the way to a certain bridge, then nothing. I could use the draw feature to create my own, but I feel like this portion would be/is mapped, and I just have a glitch or something like that. Anybody else experienced this, or is it normal?

LakeVu g3 with Navionics data. Unit is an Echomap UHD 73SV