Numerous interpretations of Noah's Ark have been built and proposed. Some were intended to be replicas, i.e. as close as possible to the original, but the original, assuming it did ever exist, is no longer. Others are looser derivatives inspired by the idea.
Contents
The Biblical description of the Ark is brief beyond the basic measures of length, height and width, and the exact design of any "replica" must largely be a matter of conjecture. Some interpret the Ark as simply a chest-like structure with rectangular sides; other reconstructions (like Ark Encounter) give it a rounded bow and stern.
Full-scale
The Bible gives the length of the ark as 300 cubits. Various cubits were in use in antiquity, but to be considered "full-scale", an Ark replica would have to be somewhere in the range from about 135 to upward of 150 meters long (ca. 440 to 500+ feet).