9818.00.03 | 00 | Spare repair parts or materials (other than nets or nettings) which the owner or master of a vessel certifies are intended for use aboard a cargo vessel, for installation or use on such vessel, as needed, in the United States, at sea, or in a foreign country, but only if duty is or has been paid under this schedule upon first entry into the United States of each such spare part or material purchased in, or imported from, a foreign country | X | Free | | 50 percent of the cost of such parts or materials |