Hi, yes - I found that. Unfortunately does not work too well - when I try to play on another computer I am in the middle of an ocean without any raft visible and die of fatique in 20 seconds or so.
I am on Linux, but principle is exactly the same - there is a place where save.rgd is stored.
Could there be something about the coordinates, or is it just that raft building is defined somewhere else, not in the savegame?