means—
| (a) | any ship or other vessel engaged in the transportation for reward of passengers or goods wholly or mainly on voyages between ports in the Republic and ports in export countries or between ports in export countries; |
| (b) | any ship or other vessel registered in an export country where such ship or vessel is utilized for the purposes of a commercial, fishing or other concern conducted outside the Republic by a person who is not a vendor and is not a resident of the Republic; or |
| (c) | any foreign naval ship; |