For the purposes of Rule 30 of the 72 COLREGS, a vessel at anchor includes a barge made fast to one or more mooring buoys or other similar device attached to the sea or river floor. Such a barge may be lighted as a vessel at anchor in accordance with Rule 30, or may be lighted on the corners in accordance with 33 CFR 88.13.
Code of Federal Regulations
[CGD 94-011, 63 FR 5731, Feb. 4, 1998]