The description of the Ark given by Almighty God in Genesis isn't that of river barges.
The Ark was a huge vessel that took years to construct and had 2 of EVERY species, not just "livestock". Its also a fact that Noah brought a male and a female of each species aboard- not 2 of the same sex, showing Almighty God's love of Normality.
It's a wonderful, epic story of redemption, but it's not history.