What Your SD Card Should Look Like

Use this when

HumVision cannot find your recording, or you want to confirm your SD card is organized correctly before heading to a launch point.

What HumVision is looking for

When you open a folder, HumVision scans for these files:

• One .DAT file (recording metadata)
• One or more .SON files named B000.SON through B004.SON (sonar channel data)
• Matching .IDX files for each .SON file (optional, used for fast playback seeking)

At least one .SON file must be present. Without it, the recording cannot be opened.

Common Humminbird folder layouts

Humminbird units use one of two layouts depending on the model and firmware version.

Layout 1: Everything in one folder

This is the most common layout on Helix units.

Sonar Files/
  R00008.DAT
  R00008.SON        ← older single-channel units use a plain .SON
  B000.SON
  B001.SON
  B002.SON
  B000.IDX
  B001.IDX
  B002.IDX

Open the folder that contains the .DAT and .SON files directly.

Layout 2: DAT in a parent folder, channels in a subfolder

This is common on Solix and some MEGA units.

Sonar Files/
  R00008.DAT        ← DAT is here, in the parent
  R00008/
    B000.SON        ← channel files are inside the subfolder
    B001.SON
    B002.SON
    B000.IDX
    B001.IDX
    B002.IDX

You can open either the parent folder (Sonar Files) or the channel subfolder (R00008). HumVision checks one level up for a matching .DAT file if it does not find one in the folder you selected.

What the folder names mean

The folder name (R00008) is the recording number assigned by the unit. The number increases with each new recording. Each recording gets its own folder or set of files.

If HumVision can't find the recording

• "No sonar channel files found" — you may have selected a parent folder that contains multiple recording subfolders. Open one of the individual recording folders instead.
• Drive is not showing up — eject and re-insert the SD card or card reader. On Windows, check Disk Management to confirm the card is recognized. On macOS, check Finder's sidebar.
• "Can't find the drive or folder" — the path to the recording was stored in your library from a previous session but the drive is not currently connected. Reconnect the card and try opening again from the library.
• Files are present but the recording won't open — confirm the .SON files are named B000.SON through B004.SON. Some file managers rename files during copy. Check that no extension was added or removed.