The route to San Francisco was very safe since it didn't go through the Indian Ocean or Malacca, so there were no worries about pirates or the like.
As Captain Wu put it, the route to San Francisco was the safest, crossing the Sea of Japan and then directly entering the Pacific Ocean. If you traveled in a straight line, you could even reach the Hawaiian Islands.
Yusuf Zuck began his undersea exploration journey.
Since Captain Wu and the others had already witnessed his abilities, when he jumped into the sea again the next day, everyone was gathered at the deck railing, talking and laughing, hoping that he would bring back even more treasures.
And indeed, he did bring back treasures, all of which were large pearls. In fact, the main reason Yusuf Zuck dove into the sea was to search for the Purple Pearl.
Unfortunately, Purple Pearls were not something one could seek at will. He found many white pearls but not a single Purple Pearl.
