Use of health services by merchant seamen.
D000293:Adolescent; D000328:Adult; D006296:Health Services / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009786:Occupational Health Services / Q000706:statistics & numerical data*; D012767:Ships; D014481:United States; D014492:United States Public Health Service