Section 178(2)(a) in The Navy (Pay And Allowances) Regulations, 1966
(a)The Lower rate of unit certificate allowance shall be payable(i)during the first ten years' engagement-on completion of two years from the date of qualifying for the unit certificate.(ii)during the period of re-engagement beyond ten years to complete the time for pension-from the date following the date of completion of ten years' service since attaining a man's rate or since attaining the age of 17 years whichever is later, if they are already qualified for the unit certificate, or from date of qualifying for the unit certificate, whichever is later.