merchant marine

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A nation's commercial ships.
• noun The personnel of a nation's commercial ships.
• noun A merchant mariner.

from the GNU version of the Collaborative International Dictionary of English.

• noun The ships owned by nationals of a particular country that are engaged in civilian commerce; also, the personnel operating those vessels. Distinguished from the navy, which contains the vessels of war.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Ships and crews dedicated to commercial, rather than military, purposes.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun conveyance provided by the ships belonging to one country or industry
• noun the crew of a merchant vessel