We are all familiar with the story of Noah and his Ark - loaded up with animals; a he and a she. Left out of the story we all know was a discussion about the size of said ark. Now we know that it was described as 300x50x30 cubits - each cubit being about a foot and a half. The argument that took place before Noah went to the big box store to buy the lumber was a pure and simple one of practicality: "How big was big enough"?
One group of advisers reasoned as follows: The goal was to board a M/F of every animal on earth - two each of every living thing. Census were taken. Calculations made and the 300x50x30, three decker raft of sorts would just about do it...it would be tight and by golly the ace in the hole here was that over time, food would be eaten, things consumed, even a certain number of premature deaths - the end of the voyage would therefore find the ark with more room per animal than when they left. It made perfect sense.
An equal number of folks argued that the ark was too small by half. Eating the food and drinking the water, consuming other supplies and the inadvertent, premature deaths of a few of the animals would be hugely outweighing the almost certain realization that with a M/F population "in pairs" - a long sea voyage..well, nature was sure to take its course.
I'm telling you all this because all we know is that Noah built the ARK to the 300x50x30 that God dictated him to build - after all God knew what He was doing and things would sort themselves out. We don't know who won the argument, who prevailed, what logic was adopted. All we know is that there was a 450,000 cubic cubit raft full up with animals to repopulate the world after the flood - supposing that the two sides of wise folks were swept away in the flood and their arguments lost in time and the deep blue sea.
But the central question remains as to building this raft to be full up for the launch or to be full up for the eventual landing. I've got my own opinions on which way to go here and I'm always surprised that there are a fair number of folks that think I'm nuts and they are right.
The parable here isn't so much the space needed at the beginning or the end of the journey, or for that matter that God said "build it thus" and there was a discussion about it notwithstanding. The parable revolves around no one knowing "going in" how long the flood would last. It was 40 days and nights - the rain part of it anyway - but no one knew that before hand so how, in the presence of the great unknown of "how long would we be afloat"?, could you possibly build the finite Ark to be just big enough for the launch only...and not for what could follow.