This question (and its corresponding answers) do a good job of explaining how the time loop influences the story, but there's one thing I still don't understand - how did the ship in the middle of the ocean get there in the first place, and how come it's deserted? And how come it stops for the crew to climb aboard?
We don't see Jess at the controls to stop the ship at all, and we never see any hint of any other crew (though we do see plenty of evidence that her time loop has occurred many times before on that very ship of course.)
Is there some symbolism that it's just driving itself that I've missed, or something else entirely?