NavList:

Brad Morris, you wrote:
"illiterates composed well over 80% of the population in 1850.  It is also possible that the population of a sailing vessel is somewhat reflective of the population as a whole.  Why just possible?  What population(s) are considered?  Does it include, say the middle east where women continue to be subjugated.  So some caution is necessary."

Yeah... Caution indeed. That number is terribly misleading relative to the American whaling industry and the background of "Moby-Dick". Literacy in New England c.1850 was above 95%, possibly even above 98%, and that covers marginalized groups, too, including women. Newspapers were everywhere. Books were widely available. Charles Dickens was famously treated like a rock star on his tour of America in 1842. Letters written by people of all social classes are abundant in primary source document archives. 

Of course, whaling ships also took non-Americans as crew, though it was not as extreme as the "model United Nations" imagined in Melville's "Moby-Dick". Needless to say (but I will), Moby-Dick is not a documentary!

The techniques of navigation, including celestial navigation, were readily available to anyone with interest and time. Literacy enabled this.

Frank Reed
PS: There's something slightly off-color about the fame of Charles Dickens in America. His books were universally read in the USA back then because they were shamelessly pirated by American publishers. As movie studios know today, many of their films have far greater fame in some parts of the world that ignore copyright.