Bushnell Backtrack D-Tour

[routeconverter]

The files stored on the device aren't recognised as anything by Routeconverter (they are called "Upload files.btk" and binary)

Does gpsbabel support these files?

The chip is a SiRF Star III GPS receiver chip in it. I'd have thought I could have seen a timestamp in there (the start data would be 16:53 2012-11-12) but nope. Maybe it's not even recording time and date

I guess it does. In the absence of documentation, the challenge is to decipher which bits and bytes carry which information in which representation. Start with well-known time and position and try to find the information as GMT time and WGS84 coordinates in the .btk file.