Sam Clemens worked on steam boats. I am not sure he ever received a license to pilot them. If that is what you are asking the answer is none.
BUT!
Isaiah Sellers was a steam boat captain. One of te Mississippi's finest we are told. He is credited, by S. Clemens, to be the first person to use the name Mark Twain as a writer.
He was a captain on the Mississippi for many years.
HOWEVER!
No record of any of his writing being publish are around any longer.
Did I add any mud to the clarity you were asking to obtain on this question?
They are called Pilots. They are extremely knowledgeable on the area in which they work and how the water affects the ship. They typically serve as an apprentice under a qualified pilot for a fairly long time.
A Mississippi cub-pilot refers to a novice or apprentice steamboat pilot on the Mississippi River. They were responsible for learning the intricate navigation of the river, such as the changing currents, sandbars, and hazards, under the guidance of an experienced pilot. Mark Twain's book "Life on the Mississippi" offers a detailed account of his experiences as a Mississippi cub-pilot.
Twain is pronounced "tw-ey-n" with a long 'a' sound.
Mark Twain lived until he was 75.
The word "pilot" has a long vowel sound for the letter "i," pronounced as /aɪ/.
mark twain
6 moons.
an hour and 51 minutes
a million years :(
The 2011 Honda Pilot is 15 ft 10.9 in long.
The word "pilot" has a long vowel sound for the letter "i".
He ate cheese long long time