With the conclusion of the First World War , Cook was reduced to his permanent rank of Boatswain .
With the conclusion of the First World War , Cook was was promoted to Chief Boatswain on January 11 , 1919 .
With the conclusion of the First World War , Cook was reduced to his permanent rank of Boatswain and was promoted to Chief Boatswain on January 11 , 1919 .