Smaller than Noah's Ark?
Perhaps the one most heavily disputed issue is the scholarly and popular literature about the Zheng He's expeditions from the Ming China to India and Africa is the size of his fleet's flagships, the so-called "treasure ships (宝船). The literalists go along with the length preserved in the literary tradition, 444 chi, cobbling together various circumstantial evidence in its support. The skeptics argue that the traditional sizes just does not make sense, on a variety of grounds (e.g., comparisons to the sizes of the reliably documented largest wooden ships from other cultures, and the existent evidence about problems people had handling those other vessels). One can see an overview of various positions e.g. in Edward L. Dreyer's book, Zheng He: China and the oceans in the early Ming dynasty, 1405-1433 (2007); for a good exposition of the views of skeptical naval architecture historian, see e.g. Christopher Wake "The Myth of Zheng He's Great Treasure Ships" (International Journal of Maritime History, vol 16 (1), pp 59-75, (2004).
In any event, no one is sure exactly how long the chi used by Zheng He's shipwrights was, but it was somewhere around a foot - making the recorded length of the treasure ships about 450 feet, or 135 meters, give or take 10% or so.
Faithfulness in reproduction can only go so far...
The controversy does not of course stop the builders of scale models of Zheng He ships, and, on occasion, full-scale models as well. (Admittedly, the treasure ship constructed in Nanjing's Treasure Boat Shipyard Park, celebrating 600th anniversary of Zheng He's expeditions, is "merely" 63 m (210 feet) long; but the on-site signage explains that it is supposed to represent merely a "mid-size" treasure ship, rather than the largest one. Incidentally, the stationary vessel is actually built from concrete, merely lined with wood on the inside and outside. I guess this will guarantee the modern treasure ship greater longevity than the original could boast...)
While Zheng He's treasure ships may be the most famous maritime vessel of the Chinese historical and literary tradition, throughout the rest of the world this role is played by an even older - and even more poorly documented vessel: Noah's Ark. The Biblical description of the ark is, of course, not much more detailed than that of Zheng He's flagships, and the archaeological evidence is, uhem, scarce. But that is not stopping the believers from building full-size a replica ark, although not near the Biblically appropriate Mt. Ararat, but in the Biblically named Hebron, Kentucky. (The money may be an obstacle, however). The length of the venerable ship? The Biblical 300 cubits became converted to 500 feet (150 meters), just a tad more than the traditional size of the Chinese Treasure Boats!
I imagine that few (if any) of the people planning Kentucky's "Ark Encounter" park are familiar with Nanjing's "Treasure Boat Shipyard", and vice versa. But I think that it would not hurt the designers and operators of the two facilities to compare notes and exchange experiences. For example, the Nanjing treasure ship's holds are mostly empty (the park's exhibits are in separate museum buildings), meanwhile the Kentucky ark will perhaps house some animatronic simulations... Zheng He's fleet is know for carrying at least some exotic animals from overseas countries to China (notably, giraffes), besides of course many thousands of its own men and horses; so here's one possibility for "enhancing" the treasure ship model...
Who needs an ark if you have a literate turtle loaded with xirang?
Incidentally, Chinese mythic/historical tradition has a Great Flood of its own, possibly even contemporaneous with the Biblical one. However, there is no ark involved. Instead of building a ship and waiting out for God to drain the waters, as Biblical Noah did, the human protagonist of the Chinese Flood story, Yu the Great, was busy handling the flood waters on the ground level, becoming the founder of the nation's flood control work. Like Noah, Yu, too, had some divine help at his work. According to one version of the story, in front of him, a yellow dragon was dragging his tail, cutting channels in the ground; behind him, a black turtle sent by the Spirit of the Yellow River was swimming, carrying xirang (息壤) - a magic substance using which dry land could be created. Pressing engraved characters on its lower shell (plastron) against the newly created land, the turtle was then giving names to the emerging mountains and rivers of China. Although I am not aware of any Great Flood theme park in China, there is apparently a Yu-the-Great-centered sculpture park in Wuhan.