Are there any charts for Lake Powell available for Coastal Explorer?
Sorry, but neither NOAA or the USACE currently distribute charts for that lake.
Not sure why I didn’t think of this when I wrote my first post, but C-MAP does produce lakes charts, so that may give you what you’re looking for, but they aren’t free. If you want to pursue this, here’s a video that goes over how to get C-MAP charts. Just be sure to find the Lakes section under “Specialty Charts.”