Some characteristics of Noah's ark include that it was made out of gopher, or gofer, wood, based upon divine building plans and that it was designed to hold restricted numbers of each of the animal species in the world. Noah's ark is described in detail in the Book of Genesis, chapter six.
Noah's ark, as described in Genesis, was 300 cubits long, 50 cubits broad and 30 cubits tall. In modern units, this is roughly 450 feet long, 75 feet broad and 45 feet tall. The ark was designed with a skylight and three floors or compartments. The compartments were intended to contain mated pairs of each of the animal species on Earth, as well as stores of every kind of edible to feed Noah, his family and the animals on board.
Noah was instructed by God to build his ark out of gopher or gofer wood but the kind of wood gofer was unknown, as of 2015. Biblical scholars have speculated that it may have been cypress, cedar or pine, or that it may even refer to a style of woven boat building used in the Middle East. There is some indirect evidence in other parts of the Bible that gofer may have been reed, rather than lumber, according to the Jewish Encyclopedia.
Noah was also instructed to completely cover the ark with pitch, both inside and out. This was not an unusual practice for ship-builders in the ancient Middle East and was presumably intended to keep it watertight during the worst rain storm the Earth has ever seen.