Genesis 6:14–16 (ESV)

14 Make yourself an ark of gopher wood. Make rooms in the ark, and cover it inside and out with pitch.

We now read that the Lord himself was speaking. He spoke directly to Noah and instructed him to build the ark. The Hebrew word used here for ark occurs only in the chapters relating the flood and in Exodus 2:3–5. There it refers to the basket made of bulrushes in which Moses was laid to be saved from drowning in the Nile.

The ark was to save Noah, and in him the church. Noah had to make the ark of gopher wood. This is the only place in the Old Testament that mentions this kind of wood. We cannot say with certainty what type of wood this was.

The construction of the ark was an impressive task. According to God’s direction it was necessary to make several rooms in the ark. There had to be three floors. The ark was a very large boat that had to be covered inside and out with pitch to make it watertight. Another peculiarity of the ark was that its proportions were such that today we would say that they represented the ideal proportions for a seaworthy vessel. If we want to know the size of the ark we need to know the length of a cubit. A cubit did not always represent the same number of centimeters. If we look at the shortest and longest possible distances for a cubit, the results are as follows:

With the smallest measure of a cubit, we arrive at:

Length                 135 m

Width                   22.5 m

Height                  13.5 m

With the longest measure, we arrive at:

Length                 180 m

Width                    30 m

Height                  18 m

Noah was also instructed to make a roof for the ark and to put a door on one side.