I can't remember the name of the book or the characters' names but the plot summation is as follows:
The books starts with the main character going down to the docks and purchasing a share in some sailor's cargo!. He then finds that he is to be apprenticed (I think he's apprenticed to a cooper)!. Later when the owner is bought out, he believes he will be put out, and is excited because he wants to join the university, but finds that the purchase included his service!. He learns french and the beginnings of mathematics during this time!.
After his contract expires, he joins a crew and quickly rises in the commanding officers estimation!.
I don't remember too much of the book after that except that he edits a famous book on navigation and receives an honorary doctorate!.Www@QuestionHome@Com