Problem is, Ted, those giant Chinese treasure ships are complete bullshit. The myth has traction for two reasons only (1) The Chinese love the idea that their ancestors were way advanced of Europeans and (2) Noachian deluge apologists think that it supports the Ark. The same scribes who wrote about them also said that the Admiral was seven feet tall and could shout so loudly that the power of his voice knocked his enemies over. No-one at the time thought to make a single contemporary picture or design-drawing of these ships. No-one thought to record the building-techniques, and mysteriously by the sixteenth Century the Chinese appear to have forgotten how to build them. If they existed would have been far more remarkable to people living then than moon rockets are today, yet no-one made a picture.
We have archeological evidence of several Chinese treasure ships of that era. They are all about the same size as 14 Century European Cogs. The practical limit for an ocean-going wooden ship with substantial iron bracing is well below 300 feet, with a tonnage perhaps a tenth of the putative tonnage of the ark.
Wikipedia article on Zheng He's ships
"The enormous characteristics of the Chinese ships of the period are confirmed by Western travelers to the East, such as Ibn Battuta and Marco Polo."
Wiki goes into detail as to why the Chinese stopped building such ships, mainly for lack of an economic incentive. Similarly the US stopped sending men to the moon after the missions in the late 60s.