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FOF Frequently Asked Questions (FAQs)

Please find  answers to commonly asked questions related to Floating OCS Facilities below.

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.

Regulatory Requirements

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Portions of 33 CFR Subchapter N, Parts 140 thru 147;

46 CFR Subchapter I-A, Parts 107 (Subpart C, Plan Approval, §107.301 thru §107.317 only) and 108 (Design and Equipment);
46 CFR Subchapter F;
46 CFR Subchapter J; and
46 CFR Subchapter S (Parts relating to 'general' stability requirements and MODUs)

Specific applicability statements within each Subchapter must be reviewed to ensure the regulations listed will apply.

Subchapter I-A: 33 CFR 143.120(c) > 46 CFR 107 Subpart C; 33 CFR 143.120(b) > 46 CFR 108
Subchapter F: 33 CFR 143.120(b) > 46 CFR Subchapter F
Subchapter J: 33 CFR 143.120(b) > 46 CFR Subchapter J
Subchapter S: 33 CFR 143.120(b) > 46 CFR 108.301 > 46 CFR Subchapter S

Yes. While the required contents of the MOM are detailed under 46 CFR 109.121, the manual is required under 46 CFR 107.305(ii). The 'path' to the MOM is 33 CFR 143.120(a) > 46 CFR 107.305(ii). §107.305(ii) refers out to §109.121 as a way not to print the same requirements in two Parts of the CFR.

The following comment summary from 47 FR 9373 (04Mar1982) attests to the intent of how 46 CFR 107 Subpart C applies to FOFs. While the context of the comments are related to stability, The Coast Guard explains that all plans applicable to the facility are listed in Subpart C. This includes the MOM with the path that is explained above.

4(b) "Two comments suggested that stability plans be submitted for Coast Guard approval, in addition to the arrangement and construction plans called for in §143.120(a). Because it is the intention of the Coast Guard that all plans applicable to the facility that are listed in Subpart C of Part 107 be submitted and because Subpart C already lists stability plans, it is not necessary to refer to stability plans in this paragraph. Paragraph (a) has been revised to make it clear that all plans listed in Subpart C that relate to the facility to be constructed are to be submitted for Coast Guard approval."

Short answer: Yes, ECA applies, however no certificate is needed (further discussion follows).


Why the ECA applies: Offshore platforms within the North American or U.S. Caribbean Sea ECAs must comply with MARPOL Annex VI but they are not required to have certificates because they do not engage "in voyages to waters under the sovereignty or jurisdiction of other Parties".


33 USC 1902(5) provides additional clarity on what ships(1) must comply with MARPOL Annex VI when in the waters of the USA, and specifically includes the ECAs.


While FOFs may not be flagged, neither MARPOL nor 33 USC limits the applicability to a vessel flying a specific flag.


Article 5(4) of MARPOL 73 states: "With respect to the ship of non-Parties to the Convention, Parties shall apply the requirements of the present Convention as may be necessary to ensure that no more favorable treatment is given to such ships." Similarly, 33 USC 1902(5)(D) states: "to any other ship, to the extent that, and in the same manner as, such ship may be boarded by the Secretary to implement or enforce any other law of the United States".


(1) 33 USC 1901 defines ships as: (12) ''ship'' means a vessel of any type whatsoever, including hydrofoils, air-cushion vehicles, submersibles, floating craft whether self propelled or not, and fixed or floating platforms.


How compliance is achieved: CG-543 Policy Letter 09-01 was written before the U.S. ECA was adopted and CVC Policy Ltr 12-04 recognized ECA, but did not directly address the OCS. With that said, an inspector should consider a certificate of inspection as proof of compliance until such time that the policy is updated or more specific guidance is provided. There is a checklist entitled "U.S. inspected ships that do not engage in voyages to ports or offshore terminals", in the back of Policy Letter 09-01. This checklist can be referenced for general guidance, but does not include the provisions of Reg 3.3.1 of Annex VI exempting emissions from sea bed mineral activities. CG-543 Policy Letter 09-01 paragraph 3.c also states: "U.S. inspected ships that do not engage in voyages to ports or offshore terminals under the jurisdiction of other Parties to Annex VI need not hold a valid IAPP Certificate and will not be issued an Annex VI endorsement on its COI. As Annex VI requirements under this guidance are incorporated into the certification process, issuance of a COI is evidence of Annex VI compliance".


Ultimately the operator is responsible for complying with ECA requirements.

 All of 33 CFR Part 153, and portions of Parts 151 and 155 are applicable, while 33 CFR Parts 154, 156, 157, 158 and 159 are NOT applicable to FOFs.

The following definitions and linked charts will further explain how the answers were reached. The linked charts for Parts 151 and 155 denote the applicability of sections within those parts.

33 CFR 151 – Vessels Carrying Oil, Noxious Liquid Substances, Garbage, Municipal or Commercial Waste, and Ballast Water (view the 33 CFR 151 Applicability Chart for FOFs by clicking here):

  • §151.03 (applicability) states that this subpart applies to each ship that must comply with MARPOL Annex I, II or V.
  • §151.05 defines a ship as “a vessel of any type whatsoever, operating in the marine environment. This includes hydrofoils, aircushion vehicles, submersibles, floating craft whether self-propelled or not, and fixed or floating drilling rigs and other platforms.”
  • §151.05 defines fixed or floating drilling rigs and other platforms as “a fixed or floating structure located at sea which is engaged in the exploration, exploitation, or associated offshore processing of sea-bed mineral resources.”
  • §151.05 further defines oceangoing ship as a ship that:
       (1) Is operated under the authority of the United States and engages in international voyages;
       (2) Is operated under the authority of the United States and is certificated for ocean service;
       (3) Is operated under the authority of the United States and is certificated for coastwise service beyond three miles from land;
       (4) Is operated under the authority of the United States and operates at any time seaward of the outermost boundary of the territorial sea of the United States as defined in §2.22 of this chapter; or
       (5) Is operated under the authority of a country other than the United States.

FOFs would fall under (4) of the definition for an oceangoing ship, in addition to the definitions of ship and fixed or floating drilling rigs and other platforms.

33 CFR 155 – Oil or Hazardous Material Pollution Prevention Regulations for Vessels (view the 33 CFR 155 Applicability Chart for FOFs by clicking here):

  • §155.100 (applicability) states that "subject to the exceptions provided for in paragraph (b) and (c) of this section, this part applies to each ship that:
       (1) is operated under the authority of the United States, wherever located; or
       (2) is operated under the authority of a country other than the United States while in the navigable waters of the United States, or while at a port or terminal under the jurisdiction of the United States.”
  • §155.110 discloses “except as specifically stated in a section, the definitions in part 151 of this chapter, except for the word “oil”, and in part 154 of this chapter, apply to this part.”

Also see the definitions previously discussed, and found under §151.05, for ship and fixed or floating drilling rigs and other platforms that apply to Part 155.

The USCG regulations applicable to cranes on FOFs are referenced from 33 CFR 143.120(a) & (b) and are summarized in the following table:

Table showing the crane regulations applicable to FOFs

The following cites are NOT required by USCG regulations for FOFs:

§107.258 (Crane certification),
§107.259 (Crane inspection and testing),
§107.260 (Rated load test for cranes),
§109.437 (Crane record book),
§109.439 (Crane certificates), and
§109 Subpart F (Cranes; general operations/maintenance, working loads and operator designation).

While the italicized cites above are not applicable via USCG regulatory requirements, they do provide guidelines that would contribute to increased safety surrounding crane inspection, maintenance, testing and operations. We highly encourage operator’s to voluntarily comply with the criteria listed in these non-applicable cites or with a newer edition of API’s Recommended Practice for Operation and Maintenance of Offshore Cranes (RP 2D). Please note that various aspects of these non-applicable USCG regulations may also be addressed by an operator’s SEMS plan under BSEE regulations.

CFR excerpts for reference:

§143.120(a) Before construction is started on a proposed floating OCS facility, the owner or operator of the facility must submit to the Coast Guard for approval all plans and information listed in subpart C of 46 CFR part 107 which relate to the facility. All plans and information must be submitted according to the procedures in that subpart. [emphasis added]

§143.120(b) The facility must comply with the requirements of subchapters F (Marine Engineering) and J (Electrical Engineering) of 46 CFR chapter I and 46 CFR part 108 (Design and Equipment). Where unusual design or equipment needs make compliance impracticable, alternative proposals that provide an equivalent level of safety may be accepted. These requirements do not apply to production systems on the facility. [emphasis added]

46 CFR 107.309 Crane Plans and Information
(a) Three copies of each of the following must be submitted:
   (1) Stress and arrangement diagrams, bill of materials, and supporting calculations for all structural components listed in API Spec. 2C, Second Edition, February 1972 (with supplement 2). [emphasis added]
   (2) Drawings of foundations and substructures with supporting calculations for support and stability of each crane under its rated load.
   (3) Plans showing the installation of the safety features required in §108.601.
   (4) Drawings of the means provided to stop motion and set brakes during a power failure.
Note to §107.309(a)(4): These plans must be submitted to the Coast Guard, if the crane is not certified. If the crane is to be certified, four copies must be sent to the American Bureau of Shipping or the International Cargo Gear Bureau, Inc.
(b) In addition to the plans and information required in paragraph (a), the following plans and information must be submitted to the Coast Guard only:
   (1) One line diagrams of the electrical power circuits of the electric power crane overload protection required in Subpart 111.50 of this chapter.
   (2) Diagrams of the hydraulic or pneumatic power and control systems, as required by Subpart 58.30-40 or 58.30-50 of this chapter, as applicable.

46 CFR 108.601 Crane Design
(a) Each crane and crane foundation on a unit must be designed in accordance with the American Petroleum Institute Specification for Offshore Cranes, API Spec. 2C, Second Edition, February, 1972 (with supplement 2). [emphasis added]
(b) In addition to the design requirements of paragraph (a), each crane must have the following:
   (1) Each control marked to show its function.
   (2) Instruments with built-in lighting.
   (3) Fuel tank fills and overflows that do not run onto the engine exhaust.
   (4) No gasoline engines.
   (5) Spark arrestors fitted on engine exhaust pipes.

Manning and Licensing

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Although not legally binding, CG Marine Safety Manual (MSM) Vol II/G.4.L.2.a (pg G4-20) refers lifeboatmen for FOFs back to 46/109.323. See the discussion for the same FAQ under MODUs (U.S. requirements near the bottom) for an explanation on the required number of lifeboatment, compared to the number and capacity of the lifeboats. MSM III/B.2.O.3 references back to MSM II/G.4.L for FOF manning.


The guidance for FOFs and intent of requirements related to MODUs (used to shape FOF guidance) are aimed at providing lifeboatmen for the boats needed to accommodate evacuation of the persons onboard (100% capacity), not providing lifeboatmen coverage for the redundant boats.


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A portable accommodation module (PAM) is considered any non-integral, enclosed space installed on a floating OCS facility and occupied by personnel for berthing, recreational, service, or industrial purposes. Examples include sleeping cabins, offices, hospitals, recreational spaces, dining spaces, lavatories, galleys, laundries, laboratories, workshops, wireline units, mudlogger rooms, ROV control rooms, dive control rooms, and any other similar spaces1. The cognizant OCMI is responsible for making determinations on whether or not a module is considered a PAM.

1 CG-ENG Policy Letter 01-16, Portable Accommodation Module Guidance, is the reference for this FAQ and contains detailed information to guide industry, authorized classification societies, and CG inspectors through the process, ranging from design and construction of the module to approval and installation.

Short Answer: The cognizant OCMI approves PAM installations, but only after certain considerations have been satisfied per CG-ENG Policy Letter 01-16, Portable Accommodation Module Guidance. Some of these considerations are best satisfied prior to, and during, the PAM construction. PAMs that address these concerns during construction may affix data placards indicating Coast Guard approval.

Long Answer: The PAM approval process, in total, begins with the approval of the module itself.

It is crucial to understand that installing a PAM, no matter the PAM size, is a modification and must comply with the same requirements as a permanent modification (plan approval, construction oversight, inspection, etc.). Policy Letter 01-16 provides a means for builders and operators of PAMs to streamline the inspection process by separating the pre-installation plan review from the installation plan review.

Modules approved under Policy Letter 01-16 are constructed using the American Bureau of Shipping (ABS) Guide for Portable Accommodations Modules (May 2014) or, if approved by the Marine Safety Center (MSC), an equivalent, alternative standard. Each approved module has a unique data plate and corresponding MISLE (Marine Information for Safety and Law Enforcement) activity attesting to its construction oversight. See Policy Letter 01-16 Enclosure 3 for detailed guidance on the construction process and standards.

Once the module has been approved and certified for use, and before installation, the operator must submit an application for inspection to the cognizant OCMI stating the purpose, general arrangement, and intended period for which the module will be on the facility. Additionally, the OCMI shall ensure the engineering plans detailing the installation have been submitted to MSC. Engineering plans, distinctly separate from module construction plans, include, but are not limited to, items such as installation location and deck strength analysis and must have MSC approval before installation.

To remove a PAM, the operator must submit an application for inspection to the cognizant OCMI, stating the removal of the PAM and intention to return to "pre" PAM configuration. See Policy Letter 01-16 5.c.vi for additional considerations.

It is incumbent upon OCMIs to engage with the installation and removal of PAMs, regardless of how "routine" it may seem to the operator or inspector.

NOTE: This FAQ addresses "new" and not "existing" PAMs. See Policy Letter 01-16 Enclosure 3 for guidance on existing PAMs.

Emergency Evacuation Plans (EEPs)

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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.

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.

Financial Responsibility

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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.

Further 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 138.15(b) states:
For the purposes of financial responsibility under OPA 90, a mobile offshore drilling unit is treated as a tank vessel when it is being used as an offshore facility and there is a discharge, or substantial threat of a discharge, of oil on or above the surface of the water. A mobile offshore drilling unit is treated as 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


Navigational Aids

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Short Answer:


Long Answer:

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 67.30-59(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

In accordance with 33 CFR 67.10-10, sound signals required on Class “A”, “B” or “C” structures have to be operated continuously, unless the sound signal can be controlled:

  1. By an attendant on the structure;
  2. Remotely by an attendant on a nearby structure; or
  3. By a fog detection device that is capable of activating the sound signal when the visibility in any direction is reduced to the range required for the facility.

Note that the “attendant” referenced in options 1 and 2 above are intended to be personnel that are able to regularly monitor local conditions and activate the sound signal when conditions diminish to the point that the signal is required. The mere presence of personnel on the facility does not satisfy attendant requirements. The following examples should aid in the explanation:

  1. If all personnel are asleep (i.e., no personnel are on tour/duty/watch), local conditions are not being monitored and the sound signal should be in operation.
  2. Facilities with personnel awake/on tour throughout the course of a 24-hour day would easily be able to monitor visibility conditions and activate the sound signal when needed.

At any time visibility conditions diminish and the sound signal is not active, the facility is out of compliance with regulatory requirements and is a risk to both navigation of vessels in the area and their crew and to the crew on the facility.

Sound signals have to be operated in regards to visibility as follows:
Class “A” structure – when the visibility in any direction is less than 5 miles; and
Class “B” and “C” structures – when the visibility in any direction is less than 3 miles (unless the District Commander prescribes a greater or lesser distance, not to exceed 5 miles).