The comment was specifically about aircraft carriers. In the wikki article it says (further down):
In 1921, it launched the Hōshō, the first purpose-designed aircraft carrier in the world to be completed,[79] and subsequently developed a fleet of aircraft carriers second to none.
If it was the "first in the world, unlikely that a "English pilot who gave the Japs info on how to build one" as said by BTK. hence my request for further information on his specific point.