Sorry for the delayed response. I've created the steps with associated screenshots from Reefmaster & the GO7 unit. I can elaborate with more details if needed.
(Each step below corresponds with a screenshot that I've attached in order)
Thank you.
1. Download XYZ values for area to be mapped
2. Open XYZ file in a table or notepad
3. Format columns and values to meet Reefmaster import standards
4, This xyz table contains over 100k rows representing elevation values/points
5. XYZ elevation values (LAT_LON_DEPTH) are saved as tracks or trackpoints
6. Once imported_elevation points are automatically display as connected tracklines and assigned RGB color red
7. Zoomed in view of tracklines that Reefmaster generates after points are imported
8. Edit trackline layer to review trackpoints
(continued in additional reply due to # of screenshots)