Species Saved. The first problem deals with how such a small ark could hold all the animal species on earth. The consensus of ancient historians and archaeologists is that a cubit was about eighteen inches long. Translating the Bible’s dimensions according to an eighteen-inch cubit, Noah’s ark was only forty-five feet high, seventy-five feet wide, and four hundred and fifty feet long (Gen. 6:15). Noah was told to take two of every kind of unclean animal and seven of every kind of clean animal (6:19; 7:2). But scientists count between one-half billion and more than 1 billion animal species.

A Localized Disaster? One possible explanation is that the flood was local in geographic scope. Noah in that case would only have to repopulate the local area and have animals to eat and sacrifice.

As evidence that the flood was not universal, it is noted that the same "universal" language of Genesis 6 through 9 is used elsewhere when something less than the whole world is meant. The people on the Day of Pentecost were said to be "from every nation under heaven" (Acts 2:5) yet the nations listed are restricted to the Roman world. Paul said in Colossians 1:23 that "this is the gospel that you heard and that has been proclaimed to every creature under heaven." Paul’s itinerary in Acts 13 to 28 shows that he went only to the Mediterranean area.

Also, the silt deposits a flood like Noah’s would have left are found only in the Mesopotamian Valley, not over the entire world. There is not enough water in the world to cover the highest mountains (7:20). Some mountains are several miles high. Waters that high would have caused problems with the rotation of the earth. The mountains in the Mesopotamian area are not nearly so high.

Finally, the size of the ark would restrict the number of species. Those from a localized region would have been more manageably housed.

A Universal Flood? Other Old Testament scholars believe there is evidence of a universal flood. The language of Genesis is more intense than that of the references noted. God’s commands to take animals of every kind would not have been required if only the life in a limited geographical area was to be destroyed. Animals could have migrated in to repopulate the region. And Genesis 10:32 declares that the whole world was populated after the flood from the eight who were saved. This would not have been true if those outside the local area had not drowned. Peter refers to the salvation of only eight (1 Peter 3:20).

The silt deposits in the Mesopotamian Valley were from a local flood(s), not the universal floods. The silt layers throughout the world are open to interpretation, including the possibility of a world catastrophe. There are also signs of dramatic changes in the position of earth’s land masses. The mountains could have taken new, far higher, shapes because of the unparalleled forces at work during the flood.

The Ark Was Large Enough. But assuming the flood was universal, the question remains as to how Noah could get all those animals in the ark. Engineers, computer programmers, and wildlife experts have all taken a look at the problem, and their consensus is that the ark was sufficient to the task.

The ark was actually a huge structure—the size of a modern ocean liner, with three levels of deck (Gen. 6:13), which tripled its space to over 1.5 million cubic feet. This equals 569 railroad box cars.

Second, the modern concept of "species" is not the same as a "kind" in the Bible. But even if it were, there are probably only some 72,000 different kinds of land animals which the ark would have needed to contain. Since the average size of land animals is smaller than a cat, less than half of the ark would be needed to store 150,000 animals—more than there probably were. Insects take only a very small space. The sea animals stayed in the sea, and many species could have survived in egg form. There would have been plenty of room left over for eight people and food storage.

Third, Noah could have taken younger or smaller varieties of some larger animals. Given all these factors, there was plenty of room for all the animals, food for the trip, and the eight humans aboard.

Wooden Ship in a Violent Storm. The ark was made of wood and carried a heavy load of cargo. It is argued that the violent waves of a worldwide flood surely would have broken it into pieces (cf. Gen. 7:4, 11).

The ark was made of a strong and flexible material (gopher wood). Gopher wood "gives" without breaking. The heavy load gave the ark stability. Also, naval architects report that a long box-shaped, floating boxcar, such as the ark, is the most stable kind of craft in turbulent waters. One former naval architect concluded: "Noah’s Ark was extremely stable, more stable in fact, than modern shipping" (see Collins, 86). Indeed, modern ocean liners follow the same basic proportions. However, their stability is lessened by the need to slice through the water with as little drag as possible. There is no reason Noah’s ark could not have survived a gigantic, even worldwide, flood. Modern stability tests have shown that such a vessel could take up to 200-foot-high waves and could tip as much as 90 degrees and still right itself.

Survival Inside the Ark. How could all these animals and humans last over one year cooped up in this ark?

There is some question as to just how long the flood lasted. Genesis 7:24; 8:3 speaks of the flood waters lasting for 150 days. But other verses seem to say it was only forty days (Gen. 7:4, 12, 17). And one verse indicates that it was over a year. These numbers refer to different things. Forty days is how long it "rained" (7:12), and 150 days speaks of how long the flood "waters prevailed" (8:3; cf. 7:24). After this it was not until the fifth month after the rain began that the ark rested on Mount Ararat (8:4). About eleven months after the rain began the waters dried up (8:13). And exactly one year and ten days after the flood began, Noah and his family emerged on dry ground (8:14).

Another answer is that living things can do almost anything they must to survive, as long as they have enough food and water. Many of the animals may have gone into hibernation or semi-hibernation. And Noah had plenty of room for food on the inside and abundant water on the outside to draw on.

G. L. Archer, Jr., A Survey of Old Testament Introduction

D. Collins, "Was Noah’s Ark Stable?" CRSQ, 14 (September 1977)

A. Custance, The Flood: Local or Global?

G. M. Price, The New Geology

B. Ramm, The Christian View of Science and Scripture

A. Reiwinkel, The Flood

J. Whitcomb, The World That Perished

_________ and H. Morris, The Genesis Flood

J. Woodmorappe, Noah’s Ark: A Feasibility Study

D. A. Young, The Biblical Flood