One big reason why Samuel Clemens called himself Mark Twain is that Clemens once wanted nothing more in life than to be a riverboat captain.
Having someone measuring and calling out depth in a river was a must for any riverboat captain trying to navigate the Mississippi.
The call mark twain means “two fathoms,” or 12 feet deep.
“Mark twain” was just barely deep enough for a boat to navigate, indicating somewhat unsafe waters, suggestive enough to suit humorist and satirist Samuel L. Clemens just fine.
