What clues show that china was far ahead of the rest of the world in naval capabilities the 1400s

First of all, there are still debates about the validity of the information about the Chinese ships of this period, but we will concentrate in the facts behind the naval achievements and advances of the Chinese Empire.

1)  During the early Ming, China  returned to the center of the maritime world because of the emperor`s idea of all seven overseas expeditions. Driven mostly by the world domination idea shared by the Emperor. The records indicate the expedition sailed throughout the Indian Ocean as far as the East coast of Africa and the Red Sea for the first time and remained unrivaled until our days.

2) The Treasure Fleet was enormous, some ships were up to 120 meters long. A Chinese ship might have many decks inside it, up to nine masts, twelve sails, and contain expensive staterooms and decks, with a crew of up to 1,500.

During these few decades in the early fifteenth century, China was the unchallenged power in the world.

China's advanced navy capabilites were very noticible because of the fleet, of over 200 ships, lead by commander Zheng He, in the early 1400s. He commanded several voyages that went as far as East Africa. Each of their ships carried hundreds of soldiers and they could reach over 120 meters in lenght, which was far larger than any other ship at the time.

i guess so you did not explain the answer clearly so i can't

here is a link that will you.