but they were unknown to Westerners until after the Book of Mormon was published.
____________________________________________
And yet the “westerners” during the Crusades somehow managed...
With perhaps one exception, the Crusaders never got into the Red Sea or Indian Ocean.
The Portugese and others, however, were all over the area from 1500 or so on. These coastal areas were well known to Europeans. It was the backlands that were unknown to well into the 19th century.