1For section 54(2) of the [1957 c. 53.] Naval Discipline Act 1957 (officers qualified for appointment as members of courts-martial) there shall be substituted the following subsection:—
“(2)No officer shall be appointed a member of a court-martial except an officer who for a period of not less than 3 years or periods amounting in the aggregate to not less than 3 years has held a commission in any of the armed forces of the Crown or been an officer in Queen Alexandra's Royal Naval Nursing Service or the Women's Royal Naval Service or in any reserve of either of those services.”.