No person may operate a vessel to which this part applies unless the certificate or lease or rental agreement required by Sec. 173.21 is carried on board in such a manner that it can be handed to a person authorized under Sec. 173.23 to inspect it. [CGD 72-54R, 37 FR 21399, Oct. 7, 1972, as amended by USCG-2003-14963, 77 FR 18700, Mar. 28, 2012]