“For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast.”
As creationists, we spend a lot of time working on our models about how we think the Flood could have happened, developing new models. The old vapor canopy model has long since been superseded by more biblical and more scientific models, such as Catastrophic Plate Tectonics or the newer Vertical Impact Tectonics.
What we should not lose sight of is the reason why God sent the Flood. The reason for the coming of the Flood is given in Genesis 6:5. “GOD saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually.” If God had chosen to destroy everyone and everything, He would have been just to do so. But God also had a plan of salvation, which we read about in Genesis 6:8, which, in my opinion, is the most beautiful verse of the early chapters of Genesis.
Noah found grace in the eyes of the LORD.
Hebrews 11 tells us: “By faith Noah, being warned of God of things not seen as yet, moved with fear, prepared an ark to the saving of his house; by the which he condemned the world, and became heir of the righteousness which is by faith.” It follows, then, that Noah was saved by grace through faith. And Ephesians 2:8 reminds Christians: “By grace are ye saved through faith”. There has only ever been one method of salvation – by grace, through faith. We just have that little bit more knowledge than Noah, so that we know Who bought that salvation, and how.