Maritime Union pickets U.S. Dept. of Commerce. Washington, D.C., May 17. More than 500 members of the National Maritime Union picketed the U.S. Commerce Department Building today in protest against what they said was indiscriminate issuance of seaman's certificates. Patrick D. Whalen, Chairman of the Baltimore branch of the NMU, said the marine workers had no quarrel with Secretary Hopkins but were directing their picketing against the Bureau of Marine Inspection and Navigation, a division of the Department