Section 123(3) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(3)Promotion.(a)Midshipmen. - On completion of 6 months' afloat training as cadet and subject to passing the Cadets' Passing Out Examination and being recommended for promotion, cadets shall be promoted to the rank of Midshipmen.(b)[ Acting Sub-Lieutenants. [Substitued by S.R.O. 5-E, dated 24th May, 1975] - On completion of [6 months'] service as Midshipmen and provided they are reported as "Satisfactory" by the Commanding Officer, Indian Naval Ship SHIVAJI, officers shall be promoted to the rank of Acting Sub-Lieutenant with seniority of the date of promotion.(c)Sub-Lieutenants. - Acting Sub-Lieutenants shall be confirmed in rank with original seniority on the day following the successful completion of the Basic Engineering Course.(d)Lieutenants. - Sub-Lieutenants shall be appointed to sea for Watchkeeping duties. They shall be promoted to the rank of Lieutenant at the discretion of the Chief of the Naval Staff provided:(i)they have obtained the Engine Room Watchkeeping Certificates;(ii)they are recommended by their Commanding Officers as fit in all respects for promotion to the rank of Lieutenant.](e)[ Officers who specialise as Constructors and are unable to obtain their Engine Room Watchkeeping Certificate, owing to the exigencies of the service, may be promoted to the confirmed rank of Lieutenant, when due for such promotion. They shall also be eligible for further promotion (acting or confirmed) notwithstanding their not being in possession of the Engine Room Watchkeeping Certificate. They shall, however, be required to obtain the said Watchkeeping Certificate within one year of becoming available for employment in the General Service.] [ ][Note:-Officers who are unable to obtain the Engine Room Watchkeeping Certificate owing to the exigencies of service may be granted the acting rank of Lieutenant at the discretion of the Chief of the Naval Staff from the date on which they otherwise become due for promotion to the rank of Lieutenant in relaxation of the provisions of sub-regulation (3)(d)(i). In such cases the officers will be confirmed in the rank of Lieutenant from the due date on obtaining the requisite certificate.] [Substitued by S.R.o. 76, dated 17th February, 1967](f)[ Cases of officers who do not secure the Engine Room Watchkeeping Certificate within 8 months of sea service shall be referred to the Chief of the Naval Staff. No officer shall be promoted before the date of his seniority as a Lieutenant calculated in accordance with sub-regulation(6)] [Substitued by S.R.o. 5-E,d ated 12th May, 1966]