But on the other hand, Noah's is a story of human depravity and the destruction of the world by God via natural disaster. Outside of the animals, and maybe a "white-washed" explanation of the sign of the rainbow as a promise of God's love, there is really nothing in this story that is G rated.
Here is a PG-13 paraphrase of the story as found in Genesis 6-9. By chapter six God is already sensing that this humanity project is not going to last forever - when He looks down upon the earth and sees the violence, wickedness and corruption, He is sorry that He ever made men and women. He is grieved in his heart. In addition to the sin there is also a passing reference to mysterious figures called the Nephilim (probably divine beings of sorts) who have begun mating with human women. It is not clear if this is part of the corruption of humanity or just a sign of the times.
God decides to wipe out the inhabitants of the earth. Noah, being the only blameless man on earth, is chosen along with his three sons and their wives to build a very specifically designed boat to preserve animals to repopulate the earth after the flood. Here it gets a little confusing, because there seem to be conflicting sets of instructions about how many animals to take onto the ark: sometimes it's a pair, and sometimes it's seven pairs. In any case, they board the ark and the rains begin, and the breath of life is removed from all the earth.
God makes a new covenant with Noah and sets the sign of the rainbow in the sky to be a reminder to GOD that he has promised never again destroy the whole earth BY A FLOOD.
If you continue on in Genesis, you will find an additional story of Noah and his sons, in which Noah plants a vineyard and one fateful day his sons come upon him drunk in the fields - naked.
I think that for older children it may be helpful to talk about how this story was told a long time ago before they understood the science that goes into the natural world, and we don't read the Bible to explain science. Even thousands of years ago people asked the same kind of questions about why these things happened, and the story of Noah is one way that they tried to understand this kind of tragedy. This is what we hold in common with our ancient ancestors in faith - we want to understand how God interacts with the world.
These are the things we continue to affirm:
- God expects us to make the best of our place in the world.
- God is saddened by the hurtful ways we treat each other.
- God ultimately wants to preserve the creation and all the life that it contains.