Todd,

  Richard Maury was 23 when he began the 3 year journey that became The Saga of Cimba.

But it is obvious throughout the book that he had a lot of previous experience.  He owned his first boat when he was 8 and by the time he was in his early twenties he had served before the mast on the full-rigged ship Tusitala.  He spent most of his life as a deep water mariner and never completed another book.

  I have the sequel to Riddle of the Sands, but it is written by another author, Sam Llewellyn.  It's The Shadow in the Sands and sounds good (Sam Llewellyn has written several good sailing books), but I haven't read it yet as I'm still trying to get a copy of Riddle of the Sands.