No need, as the movie version has:this little gem
Not straight; the previous 'good' transport. The squiggly destination is inferred to be the transport to Earth. Something went wrong, previous owner died, orbs ended up in ocean.So Sydney is probably going straight back were she came from, time travel or no (I'm guessing as much as anyone is, but the author notes mention '70s Sci-fi, and the time tunnel was the '60s, so I guess that's the reference, might be something else, but I don't know what, and I was watching TV Sci-fi in the '60s and '70s).