Building an ark (vv. 14-17). God told Noah what his task was: to build a wooden vessel that would survive the waters of the flood and keep Noah and his family safe. If the cubit mentioned was the standard cubit of eighteen inches, then the vessel was 450 feet long, seventy-five feet wide, and forty-five feet high. It had three decks, one door, and a series of small windows eighteen inches high right under the roof, providing light and ventilation. The three decks were divided into compartments (Gen. 6:14) where the various animals would be kept and where Noah and his family would live.

This vessel was designed for flotation, not navigation. It was a huge wooden box that could float on the water and keep the contents safe and dry. Dr. Henry Morris calculated that the ark was large enough to hold the contents of over 500 livestock railroad cars, providing space for about 125,000 animals. Of course, many of the animals would be very small and not need much space, and when it came to the large animals, Noah no doubt collected younger and smaller representatives. There was plenty of room in the vessel for food for both humans and animals (v. 21), and the insects and creeping things would have no problem finding places to live on the ark.