Is there any Christian theological model for a non-literal ark?

The most common debate about Noah's flood is whether the flood was global or local. I want to put this particular debate aside for a moment, and ask a different question: Did the flood happen at all? Reading the views of many (often atheists, sometimes local-flood proponents), there seems to be a pretty strong scientific case against a global flood. However, as I read about this view, I have to wonder: Wouldn't (at least according to the skeptics) a flood of sufficient scope to threaten the existence of any given animal species also suffer from most of the scientific problems associated with a global flood? And if there were a flood of limited enough scope that some species' existence were not threatened, why not just send Noah and his family across some mountain to escape the local flood? So this makes me wonder if there is a Christian theological model in which the flood, or at least the ark, is non-literal. I realize there might me more than one competing model, so I'm just asking for one. Does such a model exist? If so, please point me to whomever has proposed it. I imagine that such a model would include either or both of the following tenets, but please don't limit answers to these if there is some other approach to the theory that I have not considered: - Noah and his family escaped the flood by some means less drastic or miraculous than a boat, and the boat and animal rescue was added by later generations or authors as an embellishment to the story. - Noah and his family never existed, the world was never flooded as God's judgement, and the story is a non-real myth, meant to make a point about something other than history.