Section 122(12)(b) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(b)No officer shall be promoted to the rank of Lieutenant unless he has obtained a full Naval Watchkeeping Certificate where an officer fails to obtain a full Naval Watchkeeping Certificate before he becomes due for promotion to the rank of Lieutenant, his promotion shall be delayed correspondingly and the time thus lost shall not count as reckonable service for promotion :