HB0018 BOHAI SEA SUBMARINE WORK FOR MV TOPAS IN WEST ANCHORAGE OF QINHUANGDAO PORT FROM 0100UTC TO 1100UTC DAILY FROM 9 TO 14 MAR. ENTERING AND ANCHORING PROHIBITED WITHIN 0.4 MILES RADIUS OF 39-48.02N/119-37.82E. PASS WITH SLOW SPEED. CAUTION ADVISED. HEBEI MSA CHINA.