Plans are not required for any vessel which is a sister ship to a vessel, provided that—
(a) The approved plans for the original vessels are already on file at any Marine Inspection Office;
(b) The owner of the plans authorizes their use for the new construction;
(c) The regulations have not changed since the original plan approval; and
(d) There are no major modifications to any of the systems used.
source: CGD 83-005, 51 FR 896, Jan. 9, 1986, unless otherwise noted.
cite as: 46 CFR 169.307