Section 136.215 - Period of validity(a) A COI for a towing vessel is valid for 5 years from the date of issue.(b) For a towing vessel utilizing the TSMS option, the COI is invalid upon the expiration or revocation of the owner or managing operator TSMS certificate or the ISM Code Certificate.(c) A COI may be suspended and withdrawn or revoked by the cognizant Officer in Charge, Marine Inspection at any time for noncompliance with the requirements of this subchapter.