Subchapter M

In July 2016, the U.S. Coast Guard’s Subchapter M laid out new safety and environmental standards for towing vessels. All towing vessels subject to the regulation will need to obtain a Certificate of Inspection no later than July 19, 2022.


About Subchapter M

Subchapter M applies to all U.S.-flag towing vessels, except for:

  • towing vessels less than 26 feet, unless moving a barge carrying oil or hazardous materials
  • assistance towing vessels
  • workboats operating within a worksite
  • seagoing tugboats greater than 300 GR
  • some other inspected vessels that perform occasional towing

It supersedes the jurisdiction of the Occupational Safety and Health Administration (OHSA) and any state regulations on vessel design, construction, alteration, repair, maintenance, operation, equipping, personnel qualifications and manning.

It has been phased in over a six-year period for existing vessels, culminating on July 19, 2022. Although the law took effect in July 2016, existing vessels were not required to meet most of its requirements until July 20, 2018.


Subchapter M provides two compliance options:

  1. Coast Guard inspection: the traditional inspection model under which all inspections are conducted by the Coast Guard; OR
  2. The Towing Safety Management System (TSMS): this option allows for Coast Guard-approved Third-Party Organizations (TPOs) to inspect and certify compliance. TVIB will operate under this provision of the law.

Click here to be redirected to the Subchapter M regulation.