Teaching boys the rigging and sails, 1910 (courtesy John Fabb)

Naval Instructors in the training ship HMS Exmouth
circa 1860 Source: https://www.nmrn.org.uk/

After the general lieutenancies for warrant officers in 1903, the commissioned warrant rank of chief schoolmaster (sub-lieutenant) came into being the next year. Chief and head schoolmasters were appointed by the Admiralty on the recommendation of the Director of Naval Education. The maximum number of chief schoolmasters was fixed at three, warrant head schoolmasters were increased by ten, and there was a corresponding reduction in the number of naval schoolmaster ratings. It would be another 16 years before the ratings branch was abolished and entries were made directly to the warrant ranks.