50 CFR § 17.107 - Facilitating enforcement.
(a) The operator of a water vehicle shall immediately comply with instructions issued by authorized officers to facilitate boarding and inspection of the water vehicle.
(b) Upon being approached by an authorized officer, the operator of a water vehicle shall be alert for signals conveying enforcement instructions.
(c) A water vehicle signaled for boarding shall:
(1) Guard channel 16, VHF-FM, if equipped with a VHF-FM radio;
(2) Stop immediately and lay to or maneuver in such a manner as to facilitate boarding by the authorized officer and his or her party;
(3) When necessary to facilitate the boarding, provide a safe ladder, manrope, safety line and illumination of the ladder; and
(d) It is unlawful for any person to assault, resist, oppose, impede, intimidate, or interfere with any authorized officer or member of his or her party.