Video answer: How to transfer gamecube save files using an sd card
Top best answers to the question «Saving gamecube games without memory card»
You can use NINTENDONT to play your GameCube Games from SD Card or USB Device like HDD. It has the Option of "Virtual Saves" to SD/USB. You do not need a GameCube Memory Card. You can start it from the Homebrew Channel or if you have USBLoader GX/Wii Flow/Configurable USB Loader installed,from within the Loader.
Video answer: My wii/gamecube saves