God told Noah (Genesis 6:15) to build an ark that measured 300 cubits in length, 50 cubits in width, and 30 cubits in height—which is a ratio of 30 to 5 to 3, length to breadth to height. Until around 1858, the ark was the largest seagoing vessel of which we have any written record. Using the most conservative estimate available for a cubit (approximately 18 inches), the ark would have been roughly 450 feet long (one-and-a-half football fields) and would have contained approximately 1.5 million cubic feet of space. In 1844, when Isambard K. Brunnel built his giant ship the Great Britain, he constructed it to almost the exact dimensions of the ark —30:5:3. As it turns out, these dimensions are the perfect ratio for a huge boat built for seaworthiness and not for speed. Obviously the ark was not built for speed; it had nowhere to go! In fact, shipbuilders during World War II used that 30:5:3 ratio to build the boat (the S.S. Jeremiah O’Brien)that eventually was nicknamed “the ugly duckling”—a huge, barge-like boat (with the same ratio as the ark) built to carry tremendous amounts of cargo. How did Noah know the perfect seagoing ratio to use in building the ark? Upon whose knowledge did he draw? Brunnel and others like him had many generations of shipbuilding knowledge upon which to draw, but Noah’s craft literally was the first of its kind.
From: In Defense of the Bible’s Inspiration by Bert Thompson, Apologetics Press (2003)
For incredible pictures of a full-size ark replica go to: http://www.arkvannoach.com/
See the same builder’s half-size replica open to the public at: http://worldwidechristian.net/Noah’s%20Ark.htm