Hopefully someone in the know will provide a definitive answer.
I recently tried to circumvent the notorious save game TC corruption by "moving" my sub from Luzon Straights down to Fremantle so I could save the awesomely long list of sunk ships without having to journey 4000nm with only 256 TC. Didn't work and all I got for my effort was a CTD.
I'll figure out a way to get past the corruption in the save game files one of these days.