Section 273(6) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(6)The Captain Naval Barracks, on recommendation from the Captain, Training Establishment, may grant reasonable requests from sailors to transfer from one branch to another while undergoing the New Entry Course. If found unsuitable during the New Entry Course, men may be transferred to another branch at the discretion of the Captain, Naval Barracks.