EXHIBIT 21 SUBSIDIARIES OF HORNBECK-LEEVAC MARINE SERVICES, INC. <Table> <Caption> STATE OF SUBSIDIARY NAME INCORPORATION NAME DOING BUSINESS AS Hornbeck Offshore Services, LLC Delaware Hornbeck Offshore Services, LLC HORNBECK-LEEVAC Marine Operators, LLC Delaware HORNBECK-LEEVAC Marine Operators, LLC LEEVAC Marine, Inc. Louisiana LEEVAC Marine, Inc. Energy Services Puerto Rico, Inc. Louisiana Energy Services Puerto Rico, Inc. LEEVAC Marine, LLC Delaware LEEVAC Marine, LLC Energy Services Puerto Rico, LLC Delaware Energy Services Puerto Rico, LLC </Table> II-1