Section 178(3)(b) in The Navy (Pay And Allowances) Regulations, 1966
(b)The higher rate shall be payable 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, provided that the lower rate has been drawn for a period of two years after qualifying for the certificate.