So in the patch notes, this is posted "New items have been added, obtainable through Exploratory Voyages."

Are the items predetermined the moment you send the ships out on a voyage, or is it decided once it actually times to 0 and is ready to have the log read? I ask because all of my ships are ready to be sent out now, and I don't want to bother wasting the tanks if I have to wait for the new items to be implemented.