Check the direction of the trade winds[1]. A Portuguese sailor can easily reach the Caribbean by doing nothing except raising sail. A Chinese sailor ends up in frozen waters.

1: https://en.wikipedia.org/wiki/Trade_winds

Even without wind, the Pacific is ~3x as wide as the Atlantic? The Pacific side of a globe is impressive.

There was a theory that the islands were settled from america, someone even build a boat to prove it. I think it held out until they reached a settled island in the pacific.

You're vaguely describing Thor Heyerdahl, and his raft, the Kon-tiki.

I forgot his name

Hōkūleʻa did Hawaii to Japan in under 6 months. It successfully circumnavigated the Earth in three years.