Surfer version 11 and above opens SRF files created in Surfer 7 and above. Surfer files created in versions 6 and prior are no longer supported and cannot be opened. If you attempt to open a Surfer 6 (or older) SRF file in Surfer 11 (or newer), you will get the following error:

Surfer 5 and 6 SRF files are no longer supported by Surfer. To convert this file to a format that can be read, please open and resave it in either Surfer 7, 8, 9 or 10. For more information, please contact surfersupport@goldensoftware.com.

1. If you do not have a version of Surfer that can open the files, submit a support request containing the SRF files and any data files they use, and we will send you back the converted files. 
2. If you have a version of Surfer that can open the file type, use the script below:
   1. Copy the script below from Sub Main to End Sub.
   2. Open Scripter and press CTRL+V on your keyboard to paste the script.
   3. Change the line Shell "C:\Program Files\Golden Software\Surfer\Surfer.exe" so the version is the correct version.
   4. Change the line: Directory = file_directory = "C:\Temp\" to the desired directory that contains your SRF files.
   5. Click the Script | Run command. The new SRF files are created in the same directory with _S10 appended to the file names. These files can be opened in the current version of Surfer.

Sub Main
	'Clears all messages currently in the Immediate pane
	Debug.Clear

	'==================================
	' User Variables 
	'==================================
	file_extension = "srf"
	file_directory = "C:\temp\"
	'==================================

	'Verifies file_extension has no period and file_directory ends in a back slash
	file_extension = LCase(Right(file_extension,(Len(file_extension) - InStrRev(file_extension,"."))))
	If Len(file_directory)-InStrRev(file_directory,"\") <> 0 Then file_directory = file_directory + "\"

	'Open Surfer 10 and use that instance to run the script
	Shell "C:\Program Files\Golden Software\Surfer 10\Surfer.exe"
	Dim SurferApp As Object
	Set SurferApp = GetObject(,"Surfer.Application")
	SurferApp.Visible = True

	'Defines the types of files in the chosen directory to loop through. 
        'Directs the script to a specific error message if no files exist in the directory.
	srf_file = Dir( file_directory + "*." + file_extension)
	On Error GoTo FileError

	'Loops through all of the SRF files in the chosen directory
	While srf_file <> ""
		'Defines the name of the converted file that will be saved
		out_file = file_directory + left(srf_file, Len(srf_file)-(Len(srf_file)-InStrRev(srf_file,".")+1) ) + "_S10.srf"
		
		'Opens the SRF file in a plot document
		Dim Plot As Object
		Set Plot = SurferApp.Documents.Open(file_directory + srf_file)

		'Saves the SRF file to the Surfer 10 file format
		Plot.SaveAs(out_file)

		'Prints the name of the file that was just converted
		Debug.Print srf_file

		'Gets the next SRF file in the directory
		srf_file = Dir()
	Wend

	'Closes Surfer
	SurferApp.Quit

	Exit Sub

	'Print a meaningful error message for each file that did not grid correctly
	FileError:
	Debug.Print "Error: " + srf_file + " " + Err.Description
	Resume Next

End Sub

Updated November 2021