"On that very day Noah and his sons, Shem, Ham and Japheth, together with his wife and the wives of his three sons, entered the ark. They had with them every wild animal according to its kind, all livestock according to their kinds, every creature that moves along the ground according to its kind and every bird according to its kind, everything with wings. Pairs of all creatures that have the breath of life in them came to Noah and entered the ark. The animals going in were male and female of every living thing, as God had commanded Noah. Then the Lord shut him in." NIV translation
We see again that all were aboard the ark and it happened just as God had commanded. Then, we see that it was God who shut the door and sealed them in. It is a reminder that only God has the power to protect us and only the Father knows when all of His children are safe. In much the same way, the Father is going to tell Jesus to come back and get all of us who are His.
"For forty days the flood kept coming on the earth, and as the waters increased they lifted the ark high above the earth. The waters rose and increased greatly on the earth, and the ark floated on the surface of the water. They rose greatly on the earth, and all the high mountains under the entire heavens were covered. The waters rose and covered the mountains to a depth of more than twenty feet." NIV translation
The number forty throughout the Bible is related to the completion of the earthly trials and temptations. Here, we see that it took this long for the waters to rise up and cover everything on the earth. Meanwhile, these rising waters lifted the ark containing God's people above the judgment. In the same way, God's Word (water) lifts us up today above this fallen world.
Though we are still in it just as the ark and its passengers were, we are not submerged in the ways of the world.
"Every living thing that moved on the earth perished - birds, livestock, wild animals, all the creatures that swarm over the earth, and all mankind. Everything on dry land that had the breath of life in its nostrils died. Every living thing on the face of the earth was wiped out; men and animals and the creatures that move along the ground and the birds of the air were wiped from the earth. Only Noah was left, and those with him in the ark." NIV translation
The same thing is repeated three times in this passage and that should make us take notice. Everything on the earth outside the ark was wiped out and that is a picture of the exclusivity of Jesus Christ. All can be saved through Him but nobody can be saved outside of Him.
"The waters flooded the earth for a hundred and fifty days." NIV translation
It took that long for the waters to completely cover the earth and then for them to go down far enough for the ark to rest on a mountaintop.