46 CFR § 153.491 - Waiver of certain equipment for dedicated cargo tanks.
(a) The Coast Guard waives §§ 153.440(a)(3), 153.480, 153.481, 153.482, and 153.488 and endorses a ship's Certificate of Inspection or Certificate of Compliance allowing a cargo tank to carry a single, specific NLS cargo and no other cargo if the ship's owner -
(1) Requests a waiver following the procedures in § 153.10; and
(2) Pledges in writing that while any waiver is in effect the cargo tank will -
(i) Carry only the NLS cargo listed on the Certificate of Inspection or Certificate of Compliance;
(ii) Carry no cargo other than the NLS; and
(iii) Not be washed or ballasted unless the wash water or ballast water is discharged to a reception facility.
(b) The Coast Guard waives §§ 153.470 and 153.490(a)(2) if -