Þ It would confirm that the entire surface of the planet had been covered by water within the recent history of man. 

Þ It would confirm the factual basis for the flood legend which is present in every human culture on the planet. 

Þ It would again confirm the reliability of the early Biblical record of the human race. 

Þ It would mean that every land animal (including humans) has descended from the inhabitants of the ark. 

Þ Current theories that man descended from apes, would have to be abandoned. 

Þ The fossils would have to be interpreted as mainly a result of this flood, not the result of slow accumulation over time. 

The alleged ark is yet to be discovered by a qualified team of scientists but many seemingly valid sources have claimed to have seen it.  An excellent technical resource for more information on Noah's ark is Noah’s Ark: A Feasibility Study  by John Woodmorappe. 

According to the Biblical text Noah had 100 years to build the ark which would have been an unmistakable witness to the impending judgment of God.  Jesus not only referred to this event as a fact of history, but tied his immanent return to a time when the state of affairs on earth would be similar to those at the time of Noah (Matthew 24:37-39).  If and when the ark is found, there will once again be an enormous monument pointing toward impending judgment.  When this happens my hope is that those who have not placed their faith in Christ will wake up and to do so because their opportunity may end soon.  The primary argument for not believing that Noah’s ark is a real boat testifying to a real event is the following question: 

Þ Not all every kind of animal needed to be on board.  Neither insects nor amphibians would have been taken, based on the clear statements of the Biblical text.  Only those animals which could not have survived a year long flood needed to be on board.  Furthermore, every minor variation of animal was not present.  Wolfs, foxes, coyotes, and dogs could have come from an original dog pair. 

Þ Making the generous assumption every animal was on board, at most there would be 20,000 different species mammals, birds, and reptiles (including extinct species).   Making the very generous assumption that the average animal size is as large as a sheep - 50,000 sheep size animals would have been on board. 

Þ This was no small boat.   Noah and his family had over 100 years to construct a vessel longer than a football field and three stories high.  The total space available was equivalent to a minimum of 522 railroad stock cars.  A stock car holds 240 sheep sized animals, so the ark could have held 125,000 animals. 

Þ At most only 40% of the total space was needed for all of the animals!¹   The remainder would be used for food storage. 

Þ The dimensions of the ark have been shown to be the most stable possible dimensions for a floating vessel.  The ark was built for stability and would have been almost impossible to capsize.¹

¹ Woodmorappe, John,"The Biota and Logistics of Noah's Ark", 
    Proceedings of the 3rd Inter. Conference On Creationism, 1994.