Commercial Vessel Compliance

Policy Letters: Update to harbor assist towing beyond the boundary line and use of doublers on Subchapter M towing vessels

The Coast Guard Office of Commercial Vessel Compliance issued Policy Letter 19-01 Change 1 “Enforcement Guidance for Harbor Assist Towing Vessels When Operating Beyond the Boundary Line” to align with the National Defense Authorization Act for Fiscal Year 2021. The policy letter provides updated enforcement guidance to the Coast Guard Officers in Charge, Marine Inspection (OCMI) regarding changes to manning, credentialing, and watchkeeping requirements, applicable to harbor assist towing vessels inspected under 46 Code of Federal Regulations (CFR) Subchapter M that travel outside the Boundary Line.

Additionally, Policy Letter 21-03 “Guidance Concerning the Use of Doubler Plates for Repairs Involving Towing Vessels Subject to 46 CFR Subchapter M” was issued to provide guidance to Officers in Charge, Marine Inspection (OCMI), the Towing Vessel National Center of Expertise (TVNCOE), and 46 CFR Chapter I, Subchapter M Third Party Organizations (TPO) on the use of doubler plates for repairs involving towing vessels subject to inspection under 46 CFR Subchapter M.

Questions concerning this policy should be directed to

This blog is not a replacement or substitute for the formal posting of regulations and updates or existing processes for receiving formal feedback of the same. Links provided on this blog will direct the reader to official publications, such as the Federal Register, Homeport and the Code of Federal Regulations. These publications remain the official source for regulatory information published by the Coast Guard. 

Leave a Reply