Methuselah, however, is almost a trivial detail when compared with the monumental event which occurred in 2349 BC: The Flood. Monumental really is a fitting word for this historic event. The flood is the dividing point for early human history because it separates the time before Christ into two main segments: pre-flood and post-flood.
God inflicted this massive flood upon the earth in the year 2349 BC. Only that which was on the ark was saved. In this flood, all the fountains of the great deep burst open. The floodgates of the sky were opened (Genesis 7:11). Rain fell upon the earth for forty days and forty nights. This flood rose fifteen cubits higher than the highest mountains on the earth (Genesis 7:20). And amazingly, all of that water accumulated within one year— the year 2349 BC.
The flood was a judgment on man. The pre-flood world had refused to repent, and so they received the justice they deserved. A flood was sent upon them. A flood of such great proportions that it had never been seen before (nor will it ever be seen again). Noah and his household were the only people who survived the global flood, and that by God's grace.
Later in 2349 BC, the waters of the flood began to recede. In order to see if the earth was dry, Noah sent out from the ark a raven and a dove. The first time, he sent a raven. The second, he sent a dove. The third time, he also send a dove, but this time the dove did not come back. And thus the year of 2349 BC, according to Ussher's calculations, comes to an end.
It was not until 2348 BC that the covering of the ark was removed. It was not until 2348 BC that Noah and his household set foot in the new post-flood world. For now, Noah's household had to patiently wait a little while longer, giving praise to God for saving them from a monumental judgment.
State of the World (2349 BC): The Flood (Part 1) - Genesis 7:11
A Short Account of the Ark's Final Preparation - Genesis 7:6-9
7 More Days - Genesis 7:4-5
Noah's Obedience - Genesis 6:22