9D44 A
 The radiotelephone silence period(s) are required:
A. Twice each hour for 3 minutes duration commencing at X.00 and X.30 UTC.
B. Once each hour for 3 minutes duration commencing at X.00 UTC.
C. Four times each hour for 3 minutes duration commencing at X.00, X.15, X.30, and X.45 UTC.
D. Set by the captain of the vessel at the beginning of the voyage.
