OCSNCOE Unit Emblem (silhouettes of a self-elevating MODU, an OSV and an offshore wind turbine over a silhouette of the United States with the U.S. Coast Guard mark (i.e., racing stripe) in the background).Outer Continental Shelf National Center of Expertise (OCSNCOE)

JACK ST. MALO during offshore construction with attending OSV and Floatel VICTORY. C-ENFORCER underway with water cannons flowing. SEVAN LOUISIANA underway when initially entering the U.S. Gulf of Mexico. Platform GINA off the California coast. Block Island windfarm with attending CTV. SPARTAN 151 dockside in Seward, AK.



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General OCS Frequently Asked Questions (FAQs)

Please find answers to commonly asked questions related that pertain to an OCS activity below, regardless of unit or vessel type that is conducting the activity.

Answers in this FAQ section are not a substitute for applicable legal requirements, nor are they rules (however, some questions may have an answer that comes directly from existing regulation or policy). The answers are not intended to require or impose legally binding requirements on any party. Answers provided represent the OCSNCOE’s current thinking, after researching existing regulations and policy, as well as consultation with Coast Guard Subject Matter Experts. These answers are intended to assist industry, mariners, the public, the Coast Guard and other regulators in applying statutory and regulatory requirements. When available, the FAQ will direct the reader to the official documents, such as the Federal Register, the Code of Federal Regulations or NVICs and policies. The answers provided are subject to change with regulatory or policy updates.

General OCS Frequently Asked Questions (FAQs)

Click or tap on the question to display the answer.

General OCS FAQs
General Policy
1) What is the purpose of the Coast Guard's Marine Safety Manual (MSM)?

The MSM is a guidance document to aid in interpretation of applicable laws and regulations. It essentially builds on the regulatory requirement, as far as how to consistently apply and verify a particular requirement. The manual is not a regulation in itself. "MSM Volume II" is the most commonly used by Coast Guard Marine Inspectors during various inspection activities and is the context of this FAQ.

The MSM is divided into Volumes:

  • Vol I: Administration and Management; CIM 16000.6
  • Vol II: Materiel Inspection; CIM 16000.7B - Sections A though G of MSM Vol II became individual and independent Commandant Instructions in accordance with CH-3 to MSM Vol II (COMDTCHANGENOTE 16000 dated 20Sep2021; no content changes were associated with CH-3):
    • Marine Safety: Marine Inspection Administration, COMDTINST 16000.70 (pages A1-1 thru A7-43)
    • Marine Safety: Domestic Inspection Programs, COMDTINST 16000.71 (pages B1-1 thru B10-3)
    • Marine Safety: Inspection of Engineering Systems, Equipment, and Materials, COMDTINST 16000.72 (pages C1-1 thru C5-31)
    • Marine Safety: Port State Control, COMDTINST 16000.73 (pages D1-1 thru D7-38)
    • Marine Safety: International Conventions, Treaties, Standards, and Regulations, COMDTINST 16000.74 (pages E1-1 thru E4-3)
    • Marine Safety: Carriage of Hazardous Materials, COMDTINST 16000.75 (pages F1-1 thru F5-35)
    • Marine Safety: Outer Continental Shelf Activities, COMDTINST 16000.76 (pages G1-1 thru G6-24)
  • Vol III: Marine Industry Personnel; CIM 16000.8B
  • Vol IV: Technical; CIM 16000.9
  • Vol V: Investigations and Enforcement; CIM 16000.10A
  • Vol VI: Ports and Waterways Activities; CIM 16000.11

The excerpt that follows comes from COMDTINST 16000.70 (Change 3 of MSM Volume II (Materiel Inspection) (previously Section A of MSM Vol II), from the part that is entitled "Purpose of Marine Safety Manual, Volume II..." (COMDTINST 16000.70/A.1.E.2 on page A1-13):

"The following chapters contain information and guidance intended to promote consistent interpretation and application of U.S. and international laws and regulations related to merchant vessel inspections. The regulations and the guidance contained in this volume are not intended to cover all contingencies that may be encountered during vessel inspections. This manual generally does not restate requirements that are specifically and clearly covered in the law, Federal regulations, or international conventions. There is no substitute for experience and sound judgment to ensure that good marine practice is being followed. In addition, any information in this volume may be supplemented, altered, or waived in specific cases by the Commandant, district commander, or OCMI. To that end, it is imperative that the OCMI maintain a current and complete library containing the applicable laws and regulations."

The standard regulatory disclaimer applies, as listed on Commandant Change Notice 16000, dated 20Sep2021, promulgating the release of CH-3 to MSM Vol II (i.e., Sections A through G as individual Commandant Instructions):
"This guidance is not a substitute for applicable legal requirements, nor is it itself a rule. It is intended to provide operational guidance for Coast Guard personnel and is not intended to nor does it impose legally-binding requirements on any party outside the Coast Guard."

Published 31Dec2019; updated 28Jun2022 to reflect MSM Vol II changes.

2) What are the regulatory authorities for a Captain of the Port (COTP) and an Officer in Charge, Marine Inspection (OCMI)?

33 CFR 1.01-30Captains of the Port and their representatives enforce within their respective areas port safety and security and marine environmental protection regulations, including, without limitation, regulations for the protection and security of vessels, harbors, and waterfront facilities; anchorages; security zones; safety zones; regulated navigation areas; deepwater ports; water pollution; and ports and waterways safety.

33 CFR 1.01-20(a)Officers in Charge, Marine Inspection (OCMI), have been designated and delegated to perform, within each OCMI's jurisdiction, the following functions: Inspection of vessels in order to determine that they comply with the applicable laws, rules, and regulations relating to safe construction, equipment, manning, and operation and that they are in a seaworthy condition for the services in which they are operated; shipyard and factory inspections; the investigation of marine casualties and accidents; the licensing, certificating, shipment and discharge of seamen; the investigating and initiating of action in cases of misconduct, negligence, or incompetence of merchant marine officers or seamen; and the enforcement of vessel inspection, navigation, and seamen's laws in general. Specific procedures for appealing the decisions of the Officer in Charge, Marine Inspection, or of his subordinates are set forth in 46 CFR parts 1 to 4.

Basically, if it’s inspections-related, it is an OCMI responsibility, and all remaining compliance related functions would be the COTP responsibility.

Oftentimes, an inspector will verify regulatory compliance with items that fall under both OCMI and COTP authorities. Examples would be verifying design, equipment and operational requirements as an OCMI function and verifying MARPOL/33 CFR Subchapter O and vessel security requirements that are COTP functions. The exception would be if an OCS facility is noncompliant with 33 CFR Part 106, that would be reported to the cognizant District Commander.

See the graphic below for a summary of the COTP and OCMI authorities.

Graphic listing the authorities of the Captain of the Port (COTP) and the Officer in Charge, Marine Inspection (OCMI)

Published 31Oct2023.

3) What are the differences between the District 8 Outer Continental Shelf (OCS) Officer in Charge, Marine Inspection (OCMI) and other OCMIs?

Short answer: In accordance with the regulations, the D8 OCS OCMI has jurisdiction over MODUs, fixed and floating OCS facilities, but only when the respective unit is involved in an OCS activity, as defined in regulation, while the local OCMI would have jurisdiction over any unit or vessel not meeting the aforementioned criteria.

Additional explanation: OCMIs have a broad scope of authority for inspections and investigations related functions of commercial vessels within their area of responsibility. 33 CFR 1.01-20(a) states this delegation of authority as: "Officers in Charge, Marine Inspection (OCMI), have been designated and delegated to perform, within each OCMI's jurisdiction, the following functions: Inspection of vessels in order to determine that they comply with the applicable laws, rules, and regulations relating to safe construction, equipment, manning, and operation and that they are in a seaworthy condition for the services in which they are operated; shipyard and factory inspections; the investigation of marine casualties and accidents; the licensing, certificating, shipment and discharge of seamen; the investigating and initiating of action in cases of misconduct, negligence, or incompetence of merchant marine officers or seamen; and the enforcement of vessel inspection, navigation, and seamen's laws in general. Specific procedures for appealing the decisions of the Officer in Charge, Marine Inspection, or of his subordinates are set forth in 46 CFR parts 1 to 4."

33 CFR 3.40-5 details the D8 OCS OCMI zone as "a separate marine inspection zone, with an office located in New Orleans, Louisiana, performs the OCMI functions defined in 33 CFR 1.01-20 for all MODUs and fixed and floating OCS facilities, as those terms are defined in 33 CFR 140.10, engaged in OCS activities wherever located in the Eighth Coast Guard District." [emphasis added]

An OCS activity is defined by 33 CFR 140.10 as "any offshore activity associated with exploration for, or development or production of, the minerals of the Outer Continental Shelf." Note that most of the terms used within this definition are further defined in the same cite.

To aid in the explanation, when a mobile offshore drilling unit (MODU) is not conducting an OCS activity, it falls under the jurisdiction of the local OCMI or Captain of the Port (COTP) for the zone in which it is located. For example, a stacked MODU that needs a loadline exemption to proceed to a scrap yard would fall under the local OCMI for action.

In addition, any vessel conducting or supporting an OCS activity other than a MODU, fixed or floating OCS facility would be the responsibility of the local OCMI or COTP, depending on the question or issue.Map depicting the U.S. Coast Guard Sector boundaries in the Gulf of Mexico.

U.S. Gulf of Mexico (GoM) OCMI and COTP zones for District 8 are designated in 33 CFR 3.40. Note that there are COTP/OCMI jurisdictions that extend into the far Eastern GoM (no current OCS activities occur within these areas) that are designated for District 7 in 33 CFR 3.35.

See the COTP and OCMI FAQ above for what is included in the responsibility of each of these delegated authorities.

Published 03Nov2023.

33 CFR Subchapter N Clarifications
1) How do the different types of facilities and vessels fit under the term "unit" as they are defined in 33 CFR 140.10?

The terms that will be discussed are unitOCS facilitymanned facilityunmanned facilityfixed OCS facilityfloating OCS facilitymanned platformunmanned platformvessel, and mobile offshore drilling unit (MODU).

Unit means any OCS facility, vessel, rig, platform, or other vehicle or structure, domestic or foreign.” This definition contains some terms that are further defined within §140.10 and others that are not, but essentially contains three categories: 1) OCS facilities, 2) vessels, and 3) other vehicles or structures. For this FAQ, the discussion will focus on the OCS facility and vessels categories.

Vessel means every description of watercraft or other artificial contrivance use, or capable of being used, as a means of transportation on water.” Examples are attending vessels, standby vessels, floating production units (FPU or FPSO) and mobile offshore drilling units (MODU).

  • MODU is a defined term and examples are drillships, column-stabilized units (semi-submersibles) and self-elevating units (jack-ups). It is important to note that when a MODU is attached to the seafloor or seabed it is, in addition to being a vessel, an OCS facility.

OCS facility means any artificial island, installation, or other device permanently or temporarily attached to the subsoil or seabed of the Outer Continental Shelf, erected for the purpose of exploring for, developing, or producing resources therefrom… The term includes mobile offshore drilling units when in contact with the seabed of the OCS for exploration or exploitation of subsea resources…” OCS facility can then be divided into the defined terms of manned facility and unmanned facility and fixed OCS facility and floating OCS facility. Several of these terms can be further broken down:

  • Fixed OCS facility can be further broken down into manned facility, manned platformunmanned facility and unmanned platform. These are bottom-founded facilities with examples being conventional fixed platforms, guyed towers and compliant towers.
  • Floating OCS facility includes tension leg platforms, permanently moored semisubmersibles and Spars.

The graphic below should assist in understanding how these terms and categories fit together.

Graphic depicting the categories that fall within the 33 CFR Subchapter N definition of "unit".

This FAQ was developed in response to comments during the Fall 2023 NOSAC meeting and with the assistance of industry representative Mr. E. Roan. Published 01Nov2023.

Personal Protective Equipment (PPE)
1) What are the respiratory protection requirements for facilities, units and vessels engaged in OCS activities?

33 CFR 142.39(a) requires personnel to wear the type of respiratory protection for the atmospheres listed in American National Standards Institute (ANSI) Z88.2. The 1980 edition of this standard is listed as an incorporation by reference (IBR) at 33 CFR 140.7 (ANSI Z88.2-1980). However, the language contained within 33 CFR 142.39 does NOT reference the standard in its entirety, but makes reference to specific sections, or portions, of the standard. Note that those specific sections may refer to other sections within the standard.

33 CFR 142.39(b) requires the lessee, permittee and persons responsible for the actual operations (persons listed in §142.4) to ensure that the personnel that are entering an atmosphere specified within ANSI Z88.2-1980 follow the respirator selectionfit-testing and training requirements of the standard.

§142.39(c) also requires the equipment to be approvedused and maintained in accordance with the standard.

The following chart lists the sections of ANSI Z88.2-1980 that apply to any facility, unit or vessel that is subject to 33 CFR Subchapter N (i.e., while engaged in an OCS activity):

Subject Z88.2-1980 Citation Reference Cite
Definitions 2 Various
Selection of Respirators 6 (entire section) 33 CFR 142.39(b)(1)
Respirator Fit-Testing 6.11, 6.12 and Appendix A5 & A6 §142.39(b)(1)
Training (for wearer) 7.2.3 §142.39(b)(2)
   - Reasons for need 3.2 Z88.2/7.2.3(1)
   - Respiratory hazards & effects 4 & 6.3 §142.39(c); Z88.2/7.2.3(2)
   - Engineering Controls 3.2 Z88.2/7.2.3(3)
   - Respirator selection 6 Z88.2/7.2.3(4)
   - Respirator operation, capabilities & limitations 5, 6.5 & 6.6 Z88.2/7.2.3(5)
   - Respirator inspection, donning, fit-check & wear 7.4 & 7.6 Z88.2/7.2.3(6)
   - Respirator wear in safe & test atmospheres 7.4 & 7.6 Z88.2/7.2.3(7)
   - Maintenance & storage 8 Z88.2/7.2.3(8)
   - Recognizing & coping with emergency situations 7.1.1 Z88.2/7.2.3(9)
   - Special use/problems (as needed) 9 Z88.2/7.2.3(10)
Respirator approval 6.1, Appendix A3 §142.39(c)
   - Exceptions 1.4 Z88.2/6.1
Respirator use 7.3 thru 7.9 and Appendix A7 & A8 §142.39(c)
Respirator maintenance 8 (entire section) §142.39(c)
Special problems 9 (entire section) §142.39(c)
Oxygen deficiency/IDLH A10 Z88.2/Table 1

The respirator program requirements (e.g. Sections 3 and 10) of ANSI Z88.2-1980 are NOT invoked by 33 CFR 142.39, nor implied by any of the Federal Register (FR) Notices related to the rulemaking projects that added §142.39. The discussion of comments in the FR reveal that the worker is to be provided with the necessary equipment and training, with the persons listed at §142.4 additionally responsible for making the worker aware of the effects of not using respiratory protection when required.

Published 05Jun2020.

2) Are personnel required to be fit-tested prior to use of respiratory protection?

Yes, but only for negative-pressure respirators. 33 CFR 142.39(b)(1) requires compliance with ANSI Z88.2-1980, section 6, for individual fit testing. 6.11 of the standard requires fit-testing (qualitative or quantitative) to determine the ability of each individual wearer to obtain a satisfactory fit. It also requires each wearer of a negative-pressure respirator to be fit-tested at least annually. Fit-testing is NOT required for positive-pressure respirators.

Published 05Jun2020.

3) How often must personnel that wear respirators be trained?

Each respirator wearer must be trained prior to use and retrained at least annually. 33 CFR 142.39(b)(2) requires the wearer to be trained in the matters listed in ANSI Z88.2-1980, section 7, which could be interpreted as a 'one-time' training. However, §142.39(c) requires "use" in accordance with the standard and of the standard requires annual retraining.

Published 05Jun2020.

Emergency Evacuation Plans (EEPs)
1) Is the EEP drill required by 146.125(c)(1) required to be completed once per calendar year or once every 12 months?

Short answer: Once every 12 consecutive months.

Discussion: All elements of the EEP must be exercised through a drill or series of drills on an annual basis.

33 CFR 146.125(c)(1)"At least once a year, all the elements of the Emergency Evacuation Plan (EEP) under §146.140 relating to the evacuation of personnel from the facility must be exercised through a drill or a series of drills. The drill(s) must exercise all of the means and procedures listed in the EEP for each circumstance and condition described in the EEP under §146.140(d)(9)."

The wording is for a "year", rather than a "calendar year", and should be interpreted to mean a 12 consecutive month period. The EEP drill requirements were not part of the proposed rule (24Dec1987), but were added in the final rule (18May1989) as a response to industry comments as published at 54 FR 21568 where it was described as "annually":

"Four comments stated that the EEP regulations should contain a requirement for periodic evacuation drills. The comments stated that periodic interactive drills that test and exercise all the key elements of the EEP are needed to verify that the plan continues to be viable.
The Coast Guard agrees that the periodic drills are necessary to ensure that all personnel are familiar with the EEP. Therefore, a new § 146.125(c) has been added to require that abbreviated EEP drills be held monthly and that a comprehensive drill exercising all elements of the EEP be conducted annually. Also, a new § 146.140(e)(3) has been added to require the operator to ensure that the drills are conducted."

While some USCG operational regulations are specifically worded as a 12-month period, the majority of the types of USCG regulations are categorized as annual or "once in each year" and are treated as a consecutive 12-month period for compliance purposes. A once per "calendar year" requirement could give an extended window of time that would be outside of the intent of periodic training. As an example, a drill in Jan2019 followed by the next drill in Dec2020 could satisfy a once per calendar year requirement, but would clearly exceed the intent of annual, or once a year, training with nearly 24-months passing between drills.

Published 07Oct2021.

2) What is an "element" of an Emergency Evacuation Plan (EEP) that is referenced in 33 CFR 146.125(c)(1)? Does the annual drill include all equipment (i.e., lifeboats) listed in the EEP?

Short answer: Elements are the components that make up the EEP and yes, the annual drill includes "all" equipment that is listed in the EEP.

Discussion: The phrase "all elements of the Emergency Evacuation Plan" as listed in the emergency drill requirements has often been questioned as to what it really means. Let’s take a look…

33 CFR 146.125(c)(1)"At least once a year, all the elements of the Emergency Evacuation Plan (EEP) under §146.140 relating to the evacuation of personnel from the facility must be exercised through a drill or a series of drills. The drill(s) must exercise all of the means and procedures listed in the EEP for each circumstance and condition described in the EEP under §146.140(d)(9)." [emphasis added]

The term "element" was added to the regulation with the final rule (published 18Mar1989) by the USCG in an effort to address industry comments to the proposed rule (published 24Dec1987).

Please note that the first sentence in the cite states "elements of the EEP under §146.140 relating to the evacuation of personnel from the facility". The requirements of the EEP relating to personnel evacuation are detailed in §146.140(d)(9) through (12) and include recognized circumstances that would place the facility or its personnel in jeopardy and for which a mass evacuation would be recommended. Fires, blowouts, approaching hurricanes and ice floes are specifically mentioned as examples of circumstances that would recommend an evacuation and collisions are another circumstance that is often included in typical EEPs that would initiate an evacuation.

The second sentence in the referenced cite states that "the drill(s) must exercise all of the means and procedures listed in the EEP for each circumstance" [emphasis added] to further stipulate what is required to satisfy the drill requirement.

Means and procedures are listed at §146.140(d)(12) as those for:

  1. retrieving persons from the water during an evacuation;
  2. transferring persons from the facility to the designated type of evacuation method (e.g. designated standby vessels, lifeboats or other evacuation craft);
  3. retrieving persons from the evacuation craft that they were transferred to in the previous requirement; and
  4. the ultimate evacuation of all persons to land, another facility or other location reasonably out of danger for the specific circumstance for the evacuation.

The District Eight OCS OCMI (responsible for the OCS activities on the U.S. OCS in the Gulf of Mexico) has interpreted §146.125(c)(1) "to mean that all lifeboats aboard a facility, shall, at a minimum, be launched with assigned lifeboat crew in order to fulfill the requirements of the annual emergency evacuation drill" in section 5, paragraph a, of D8(OCS) Policy Letter 01-2020, dated 19May2020. The policy letter goes on to discuss alternatives to this requirement in paragraphs 5.d through 5.f.

In the context of lifeboats/capsules, some have questioned if there is a need to test "all" of the boats for units or facilities with multiple boats, or if demonstrating the means and procedures with one, or a sampling of boats, would satisfy the intent. Note that the referenced cite states "all of the means and procedures" and the D8 OCS OCMI has reiterated this in Policy Letter 01-2020.

Also note that while the focus tends to be on lifeboats with this annual requirement, the cite requires exercise of all of the means and procedures for each circumstance that are stipulated in the EEP.

Published 07Oct2021.

Financial Responsibility
1) Is a fixed OCS facility, floating OCS facility (FOF) or a Mobile Offshore Drilling Unit (MODU) required to demonstrate Oil Spill Financial Responsibility (OSFR) and/or hold a Certificate of Financial Responsibility (COFR)?

Short answer: Fixed OCS Facilities and FOFs are required to demonstrate OSFR and MODUs are required to carry a COFR for a tank vessel or a non-tank vessel based on its operation.

Discussion: The requirements for an OSFR are found in 30 CFR 553 and the requirements for a COFR are found in 33 CFR 138.

This is based on 30 CFR 553.10:
(a) This part applies to any COF [Covered offshore facility] on any lease or permit issued or on any RUE [Right-of-use and easement] granted under the OCSLA or applicable State law.
(b) For a pipeline COF that extends onto land, this part applies to that portion of the pipeline lying seaward of the first accessible flow shut-off device on land.

Covered Offshore Facility (COF) in 30 CFR 553.3 means a facility:
(1) That includes any structure and all its components (including wells completed at the structure and the associated pipelines), equipment, pipeline or device (other than a vessel or other than a pipeline or deepwater port licensed under the Deepwater Port Act of 1974 (33 U.S.C. 1501 et seq.)) used for exploring for, drilling for, or producing oil or for transporting oil from such facilities. This includes a well drilled from a mobile offshore drilling unit (MODU) and the associated riser and well control equipment from the moment a drill shaft or other device first touches the seabed for purposes of exploring for, drilling for, or producing oil but it does not include the MODU; and…,

33 CFR 138.20(b) states:
For the purposes of applying the evidence of financial responsibility required under OPA 90 and this subpart and the limits of liability set forth in subpart B of this part, and in addition to any OPA 90 offshore facility evidence of financial responsibility requirements that may apply under 30 CFR part 553, a mobile offshore drilling unit is treated as -
   (1) A tank vessel when it is being used as an offshore facility; and
   (2) A vessel other than a tank vessel when it is not being used as an offshore facility.

33 CFR 138.230(d) states:
Offshore facilities. The OPA 90 limit of liability or offshore facilities other than deepwater ports, including for any offshore pipelines, is set forth at 30 CFR 553.702.

OSFR and COFR Applicability
  Oil Spill Financial Responsibility Certificate of Financial Responsibility
Mobile Offshore Drilling Unit No Yes
Floating OCS Facility Yes No
Fixed OCS Facility Yes No


Published 08Oct2020; cites updated 01Jul2022 to reflect 01Dec2021 amendments to 33 CFR Part 138.

2) Does an FOF need to obtain or maintain a COFR before it arrives on location and BOEM's OSFR requirements take effect (i.e., during "tow-out")?

Short answer: FOFs that have been determined not to be vessels by the OCMI are not subject to the COFR requirements of 33 CFR Part 138.

Discussion: The question of whether a COFR applies to an FOF during the "tow-out" of the FOF from the quayside facility/construction yard to the installation location on the OCS has been a longstanding question. The Coast Guard revisited this question with internal discussions between the National Pollution Funds Center (NPFC), Headquarters and District Eight legal offices, District Eight OCS OCMI staff and the OCSNCOE during February of 2023.

Research and discussion affirmed that the COFR requirements imposed by the Oil Pollution Act of 1990 (OPA 90), 33 U.S.C. 2701-2761, and 33 CFR Part 138 that implements COFR requirements apply to vessels. Therefore, if an FOF is determined not to be a vessel, as evidenced by the issuance of a non-vessel determination letter in accordance with CG-OES Policy Letter 01-22, the requirements of 33 CFR Part 138 do not apply to these facilities during the tow-out phase of their construction and installation.

Note that the definitions in 33 U.S.C. 2701 and 33 CFR Part 138.220 are specific in regard to "vessels" and types of facilities and are essential to the applicability of a COFR. These definitions differ from more inclusive definitions of "ship" (i.e., vessel) in 33 CFR Subchapter O and MARPOL.

This non-applicability only applies to the USCG's COFR regulations and requirements if the facility is determined to be a non-vessel. The OSFR is a separate coverage found in BOEM regulations at 30 CFR 553 and provides financial responsibilities associated with the lease and lease-related operations.

NPFC issues a COFR to vessels in accordance with 33 U.S.C. 2716(a) and the regulations that implement the statute. OCS facilities (i.e., offshore facilities) have their own set of requirements under 33 U.S.C. 2716(c).

If an FOF is determined to be a vessel, a COFR would apply and a further determination of the correct limit of liability would need to be considered. This would be in addition to any OSFR requirements for OCS facilities that are determined to be vessels.

Published 14Mar2023.

Navigational Aids
1) Do obstruction lights need to be level and focused?

Short Answer: Yes.

Discussion: (Note: This answer is based on conventional incandescent-type light assemblies. Manufacturer’s instructions should be consulted for LED lanterns or retrofits to ensure compliance with advertised/intended characteristics and range.)

Part 1: Leveling

The "ridges" of the Fresnel lens found on obstruction lights serve a very important purpose. These ridges condense the light to the center of the lens and send out a type of light beam to meet the required range. The range or visible distance for offshore structures depends on the structure classification and are summarized as follows (see 33 CFR 67.01-15 for requirements/information related to the classification of structures):

Class "A" structure - visible distance of at least 5 nautical miles (33 CFR 67.20-5).
Class "B" structure - visible distance of at least 3 nautical miles (33 CFR 67.25-5(a)).
Class "C" structure - visible distance of at least 1 nautical mile (33 CFR 67.30-5(a)).

If the light is not level, the focal plane will either be above or below the vessel. Either condition could reduce the required range, resulting in non-compliance with regulations and not meeting charted characteristics. See the graphical depiction below.

Graphic depicting focal planes of level and non-level aids to navigation lanterns

The leveling of the lantern can be checked via the built-in bubble levels of some lanterns or with the method displayed below (utilized by U.S. Coast Guard short-range aids to navigation technicians).

Graphic depicting how to verify the leveling of an aids to navigation lantern

Part 2: Focusing

There is another issue, especially on larger lights, that has to do with the “focus” of the light. For the light to be in focus, the lamp needs to be lined up with the center of the Fresnel lens. To check this, there are sighting marks (an "O" and "X" pair or two "X" pair) marked at 180° increments on the outside of the lens. When looking through the "O" to the "X" on the opposite side (180°) of the lens, the lamp should fall between the two sighting marks with the sighting marks aligned. The most common issue with the focus on certain model lights is when the bracket for the lamp changer mounts is installed upside down, which moves the lamp out of the focal plane of the lens.

The graphic below illustrates how to verify that a lantern is properly focused.

Graphic depicting how to verify the focusing of an aids to navigation lantern

Published 19Apr2021.

Dynamic Positioning (DP) Systems
1) Does the U.S. Coast Guard consider a vessel equipped with a dynamic positioning (DP) system to be self-propelled?

Short Answer: Yes, in most circumstances.

Discussion: While USCG regulations do not explicitly mention DP systems, the topic has been discussed in numerous CG policies, guidance and legal reviews.

Note: Additional case-by-case reviews and determinations may have been made by the CG in regard to DP as propulsion, but only those that have been available to the public are discussed in this explanation.

NVC 8-68 first addressed this issue when released on November 15, 1968, due to "an increasing number of non-self-propelled units being equipped with positioning machinery, steering aids and propulsion assist units." In this NVC, the CG policy on tunnel type "thrusters" and "kickers" used solely for transiting locks and/or canals would not be considered as a basis for classifying a vessel as self-propelled. However, the NVC went on to say that "vessels equipped with directional maneuvering equipment and/or substantial propulsion assist units will normally be considered as self-propelled vessels" regardless of if a towing vessel was employed in the operation.

NVC 8-68 was cancelled by Change 1 to Marine Safety Manual Volume II (MSM II) on July 7, 2014, and the language of the policy was condensed and included at MSM II A.6.F (pages A6-6 and A6-7). The policy was modified for vessels equipped with directional moving equipment to note that "this would include dynamic positioning (DP)". MSM II A was moved to COMDTINST 16000.70 on Sep 20, 2021, but the policy remained the same:

"To further clarify, unidirectional tunnel type "thrusters" and "kickers" used solely for transiting locks and/or canals would NOT be considered a basis for classifying a vessel as self-propelled. Vessels equipped with directional maneuvering equipment and/or substantial propulsion assist units will normally be considered self-propelled (this would include dynamic positioning (DP)); notwithstanding the fact that a towing vessel may be employed in the operation."

CG-094 (Judge Advocate General and Chief Counsel) issued a memorandum to CG-5 (Assistant Commandant for Marine Safety, Security and Stewardship) on February 11, 2011, with the subject of "Potential Legal Issues Associated with Vessels Employing Dynamic Positioning Systems" and the redacted memo was included as Appendix I to the Report of Investigation for the MODU DEEPWATER HORIZON casualty. The memo thoroughly discusses the law and history surrounding vessels and the classification of being self-propelled. At paragraph 23, the memo concludes that:

"Under current law, a watercraft operating with a DP System is an underway, self-propelled vessel, and subject to all the regulatory requirements of "traditional" vessels."

The USCG Marine Safety Center (MSC) states that "DP systems are propulsion control systems and are considered as vital systems" in section 4 of MSC Plan Review Guidance Procedure No. E2-24, dated December 14, 2021. The previous revision of the procedure, dated November 9, 2011, essentially stated the same thing, although in less direct verbiage. MSC Technical Note 02-11, CH-1, dated December 11, 2020, states in paragraph 2.b that "DP systems are considered to be a vital component of the propulsion control system" and goes on to say that "DP systems are routinely used as the primary maneuvering system during critical operations".

Frequently asked questions are posted on both the NAVCEN and OCSNCOE websites that state that a vessel that is using DP to maintain position is considered as underway, not making way in regard to the Navigation Rules and should be marked by navigation lighting or dayshapes to indicate that condition.

While a DP system may have the primary purpose of station keeping or proceeding along a specific path (usually for an industrial purpose, such as pipe laying or cable laying), the CG has considered systems that have the ability to move and maneuver a vessel as a means of self-propulsion for more than 50 years and has reiterated that DP systems fall within that category.

Published 09Jan2024.