(a) Scope of power to search conveyance. The power to board and search conveyance under section 287(a)(3) may be used with respect to all conveyances only in those districts having border patrol operations. In the other districts, that power shall, unless prior Central Office approval in obtained be used only with respect to aircraft and vessels within the territorial waters of the United States.

(b) Power to search conveyance under section 235(a). The power to board and search conveyance conferred by section 235(a) may be used in all districts. That section confers such power upon power upon immigration officers who have reason to believe that aliens are being brought into the United States upon the conveyance to be searched and places no limitation as t be distance between the conveyance and the external boundary of the United States.

(c) Authority to establish permanent highway traffic checkpoints. Regional office plans to establish additional permanent highway traffic checkpoints will be submitted to the Associate Commissioner Enforcement for his review and approval. All requests must meet outstanding Supreme Court decisions relating to Service operation of checkpoints.