§ 91. Clearance; vessels

(a) When required; vessels of United States
Except as otherwise provided by law, any vessel of the United States shall obtain clearance from the Customs Service before proceeding from a port or place in the United States—
(1) for a foreign port or place;
(2) for another port or place in the United States if the vessel has on board foreign merchandise for which entry has not been made; or
(3) outside the territorial sea to visit a hovering vessel or to receive merchandise while outside the territorial sea.
(b) When required; other vessels
Except as otherwise provided by law, any vessel that is not a vessel of the United States shall obtain clearance from the Customs Service before proceeding from a port or place in the United States—
(1) for a foreign port or place;
(2) for another port or place in the United States; or
(3) outside the territorial sea to visit a hovering vessel or to receive or deliver merchandise while outside the territorial sea.
(c) Regulations
The Secretary of the Treasury may by regulation—
(1) prescribe the manner in which clearance under this section is to be obtained, including the documents, data or information which shall be submitted or transmitted, pursuant to an authorized data interchange system, to obtain the clearance;
(2) permit the Customs Service to grant clearance for a vessel under this section before all requirements for clearance are complied with, but only if the owner or operator of the vessel files a bond in an amount set by the Secretary of the Treasury conditioned upon the compliance by the owner or operator with all specified requirements for clearance within a time period (not exceeding 4 business days) established by the Secretary of the Treasury; and
(3) authorize the Customs Service to permit clearance of any vessel to be obtained at a place other than a designated port of entry, under such conditions as he may prescribe.