There is a booklet (which I have a copy of) called "Manx Saga of the Sea - Karran Fleet" in which a Mr. T. W. Karran is mentioned as the author of "A Tale of the Seas", a story of his family who sailed the world. His father was Captain George Christian Karran one of three sea-faring brothers, all out of Castletown. Two other brothers were businessmen (one was in Liverpool) and another was a Reverend. The father of the six was John Karran. I have detailed information on all of them if you are interested. Also in the booklet is a story by Tessa Kinvig (T. W. Karran's sister I believe) called "The Children of the "Manx King"". Tessa was born on the Manx King. These Karrans owned a fleet of sailing ships over the years. This occured in the late 1800's. A number of officers who served on these ships are mentioned by name but none of them are your Cojeen. This most likely would be a good place to start looking though.
Gerry Karran