46 CFR 137.310: External survey program for towing vessels
Last reviewed: October 14, 2026
This section covers towing vessels that use the TSMS option and show compliance through an external survey program. The owner or managing operator must have a TPO surveyor examine the vessel, follow the examination rules, and support the surveyor with TSMS content. Drydock and internal structural examinations must be documented in a report.
Applies toIt applies to the owner or managing operator of a towing vessel that has selected the TSMS option and has chosen to demonstrate compliance through an external survey program.
What it says
The owner or managing operator must have a surveyor from a TPO examine the vessel at the intervals prescribed in § 137.300.
46 CFR 137.310(a)(1)“Have the vessel examined by a surveyor from a TPO at the intervals prescribed in § 137.300;”
The owner or managing operator must ensure the examination is conducted in accordance with § 137.325.
46 CFR 137.310(a)(2)“Ensure the examination is conducted in accordance with § 137.325;”
The owner or managing operator must ensure the TSMS applicable to the vessel includes policies and procedures for complying with this section.
46 CFR 137.310(a)(3)“Ensure the TSMS applicable to the vessel includes policies and procedures for complying with this section; and”
The owner or managing operator must make the applicable sections of the TSMS available to the surveyor.
46 CFR 137.310(a)(4)“Make the applicable sections of the TSMS available to the surveyor.”
The drydock examination and internal structural examination must be documented in a report containing the information required in § 137.135.
46 CFR 137.310(b)“The drydock examination and internal structural examination must be documented in a report that contains the information required in § 137.135.”
Common questions
Who must have a TPO surveyor examine a towing vessel under the external survey program?
The owner or managing operator of a towing vessel that has selected the TSMS option and chosen to demonstrate compliance through an external survey program must have the vessel examined by a surveyor from a TPO.
“Have the vessel examined by a surveyor from a TPO at the intervals prescribed in § 137.300;”
How often must the external survey examination happen?
The examination must occur at the intervals prescribed in § 137.300. This section does not give the intervals itself.
“Have the vessel examined by a surveyor from a TPO at the intervals prescribed in § 137.300;”
What must the drydock and internal structural examination report contain?
The report must contain the information required in § 137.135.
“The drydock examination and internal structural examination must be documented in a report that contains the information required in § 137.135.”
The text of 46 CFR 137.310
Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR
External survey program
(a) The owner or managing operator of a towing vessel that has selected the TSMS option and who has chosen to demonstrates compliance through an external survey program must:
(1) Have the vessel examined by a surveyor from a TPO at the intervals prescribed in § 137.300;
(2) Ensure the examination is conducted in accordance with § 137.325;
(3) Ensure the TSMS applicable to the vessel includes policies and procedures for complying with this section; and
(4) Make the applicable sections of the TSMS available to the surveyor.
(b) The drydock examination and internal structural examination must be documented in a report that contains the information required in § 137.135.
Sections it refers to
The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.