HB0050 BOHAI SEA SUBMARINE WORK FOR MV YU MING IN EAST ANCHORAGE OF QINHUANGDAO PORT FROM 0300UTC TO 1000UTC 24 JUL. ENTERING AND ANCHORING PROHIBITED WITHIN 0.4 MILES RADIUS OF 39-45.83N/119-49.05E. PASS WITH SLOW SPEED. CAUTION ADVISED. HEBEI MSA CHINA.