GD209/21 ZHU JIANG KOU GEOLOGICAL SURVEY WORK BY M/V “HUI TONG 628” “MEI HANG 8” IN AREA BOUNDED BY 22-10-00N 113-45-31E，22-08-10N 113-45-31E，22-07-51N 113-44-35E AND 22-08-57N 113-42-31E FROM 15 SEP. TO 30 OCT. SIGNAL LIGHTS AND SHAPES WILL BE EXHIBITED ADVISED TO AVOID GUANGDONG MSA CHINA