I have found more information on CAPTAIN JOSIAH NICKERSON KNOWLES. He was born on Cape Cod, Massachusetts, to a family of sea Captains in the 1830s.
Josiah Knowles is said to have returned home after his shipwreck experience but later returned fourteen years later. He was sailing from San Francisco in the ship "GLORY OF THE SEAS" and bound for Liverpool. On the 7th of March 1872, he made a brief stop at Pitcairn Island again.
A link to his Diary is posted below :http://www.nobbly.com/archive/stories/wildwave.html