Hello I recently recorded sonar on my helix 12 and I’m trying to upload it to reef master but I can’t seem to get the .idx file to work can any one help me?

To load Humminbird sonar log files into ReefMaster you need to select the .DAT file that belongs to the recording. This will look something like RecXXXX.DAT and be located in the folder above the individual .IDX and .SON files.
Please give that a try and let me know if you are still having issues.