Translation of vorläufig

In the meantime I am listening to some Spanish CDs. They are intended for the car, but no one can tell you when to listen to it, how many times and how often. Please understand that I work a lot.
The writer describes this situation by putting the persons into a natural environment. On one side there was no shade and there weren't any trees, he says. This description can be interpreted.
We left and went back to the boat which took us back to the big vessel. We started our journey back to the main land. It was already late and from the main land, it was still a four hour drive back.