How many levels did Genesis specify for Noah's Ark?

Genesis specified three levels for Noah's Ark.

Genesis 6:16 describes the ark as having lower, second, and third decks. The same verse mentions a window and an opening or door, while earlier instructions describe compartments and the use of pitch to make the vessel watertight.

These details form part of the Bible's brief construction description. The text gives the ark a length of 300 cubits, a width of 50 cubits, and a height of 30 cubits, so the three-level arrangement fits the narrative's image of a large, organized preservation vessel.

Later artwork and modern replica projects often add extensive internal layouts, animal stalls, or engineering features. Those additions are interpretations, not measurements supplied by Genesis. The explicit number of decks in the biblical account is three.