To amend title 46, United States Code, to require merchant mariners' documents for certain seamen.

Amends Federal law relating to unlicensed shipping personnel to require merchant mariner's documents for individuals serving on a vessel of at least five gross tons (currently, at least 100 gross tons), subject to certain exceptions, including small passenger vessels (currently, including vessels operating only on rivers and lakes, except the Great Lakes). Removes provisions excepting barges....