Outer Continental Shelf National Center of Expertise (OCSNCOE)

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Frequently Asked Questions (FAQs)

Please find  answers to commonly asked questions below. Note that questions are categorized by unit or vessel type.

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.

Mobile Offshore Drilling Unit (MODU) FAQs

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Is the number of lifeboatmen based on the total number of lifeboats onboard or on the number of lifeboats needed for 100% coverage of persons onboard (POB), since these types of units are required to maintain redundancy in lifeboat capacity?

Short answer: It is based on 100% coverage (but could vary/be increased by the Flag State Administration). Let’s take a further look…

Foreign-flagged units are pretty straightforward in that the Safe Manning Document sets the number of lifeboatmen required by the Administration. Many administrations base this off of the total number of lifeboats onboard.

Let’s look at some of the applicable cites to see the intent/how the minimum number would be determined:
2009 MODU 14.10.5 requires certificated persons to be placed in command AND second-in-command of EACH lifeboat. Based on this cite, each lifeboat is required to have 2 lifeboatmen (note that this is not based on the capacity of the lifeboat, but is a straight 2-per lifeboat requirement). A typical drillship example with 6 lifeboats provided, 3 on each side (100% POB coverage on each side), would need 12 lifeboatmen based on the wording in this cite. The majority of Administrations choose to use the formula of 2 lifeboatmen multiplied by the total number of lifeboats to obtain the required number of lifeboatmen to list on their Minimum Safe Manning documents.

But wait, 2009 MODU 14.10.4 requires sufficient certificated persons onboard to launch and operate the survival craft TO WHICH PERSONNEL ARE ASSIGNED. 2009 MODU 14.10.5 works in concert with 14.10.4. This puts an interesting twist to our ‘typical’ drill ship example, and the station bill will need to be consulted to determine the appropriate number of lifeboatmen based on the boats to be used. A typical drillship meets the design and equipment requirements of 100% capacity on each side (2009 MODU 10.3.1) with 3 lifeboats on each side, but common practice across the industry is to assign personnel to the 4 fwd lifeboats as their primary abandonment location/station.

Some examples of lifeboatmen numbers that would meet the intent in our drillship example, in accordance with 2009 MODU 14.10.4 & 14.10.5:
   • 3 lifeboats assigned (100% POB coverage), port or starboard boats (depending on scenario) = 6 lifeboatmen required
   • 4 fwd lifeboats assigned (exceeds 100% POB coverage, but personnel are assigned to 4 boats) = 8 lifeboatmen required

2014 SOLAS III/10.4 helps to check the intent and is a little clearer than the MODU Codes, as it uses “each survival craft to be used” in the certificated person(s) requirement.

Essentially, an Administration that requires 12 lifeboatmen would cover most any muster/abandonment assignments scenario on our typical drillship example. If an Administration requires only 6 lifeboatmen on our example, the station bill/abandonment station assignments should reflect that arrangement (6 lifeboatmen wouldn’t be sufficient if the 4 fwd boats were being utilized).

Note: If an Administration requires more lifeboatmen than the station bill/boat assignments require, the number stipulated on the Minimum Safe Manning document MUST be adhered to. If the station bill/boat assignments require more than the Administration stipulates, the required number set forth in the applicable MODU code must be complied with.

1989 MODU 14.9.5 and 14.9.4 are the same as the 2009 MODU cites discussed above.

The MODU Code (1979) does not specifically address the requirement related to manning of survival craft and the requirement will be stipulated by the Administration on the Minimum Safe Manning document. Note that ‘emergency procedures’ are located within Chapter 10 of the 79 Code, compared to Chapter 14 of the 89 & 09 Codes.


U.S. requirements follow a similar approach for MODUs. 46 CFR 109.323(c) requires a person to be placed in charge of each survival craft TO BE USED. §323(c)(1) requires them to be trained/certificated for those duties and §323(c)(2) requires the second-in-command for lifeboats permitted to carry MORE THAN 40 persons (41 POB and higher). Note that the biggest difference is that the lifeboat capacity determines when the second lifeboatman is required.

As supplementary guidance to the regulations, CG Marine Safety Manual Vol III/B.2.B.2.f discusses lifeboatmen and when/how many are required and uses the statement “each survival craft to be used” as well. This specific MSM cite is for mechanically-propelled vessels of 100 GRT or more, but is referenced as footnote 15 in B.2.O.1 (MODU sample manning).


Conclusion: Both IMO and U.S. requirements are aimed at providing lifeboatmen for the boats needed to accommodate evacuation of the persons onboard (100% of POB capacity), not providing lifeboatmen coverage for the redundant boats.

Foreign flagged MODUs choosing to comply with the "Option A" requirements of 33 CFR 143.207(a) must comply with the design and equipment requirements of 46 CFR Part 108, as applicable to the build date of the MODU. 46 CFR Subchapters F & J are not applicable as the paths to those subchapters are located in 46 CFR Part 107 (§107.231(a)), to which Option A MODUs are not subject. 46 CFR Subchapter S applies as the path to that subchapter is located at 46 CFR 108.301.

Option A MODUs will also typically comply with the operating requirements of 46 CFR 109, per 33 CFR 146.205(a).

Regulatory paths:
33 CFR 143.207(a) > 46 CFR Part 108 (including requirements of 46 CFR Subchapter S, via §108.301)
33 CFR 146.205(a) > 46 CFR Part 109

Additional regulatory guidance:
CG Marine Safety Manual (MSM) Vol II, Section G, Chapters 1 & 3

Note that with the cancellation of NVIC 3-88, there is no regulatory guidance allowing the use of NVIC 4-78 (46 CFR 109, Appendix A) for Option A MODUs.

Floating OCS Facility (FOF) FAQs

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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.

Fixed Facility (Platform) FAQs

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Short answer: The equipment listed in 33 CFR 144.01-15. “The equipment required for a lifeboat is a bailer, boat hook, bucket, hatchet, lantern, life line, two life preservers, matches, full complement of oars and steering oar, painter, plug, and rowlocks, of the same type, kind, and character as required for lifeboats carried on vessels engaged in navigating bays, sounds, and lakes other than the Great Lakes, and rivers.”

Additional explanation: Lifeboats that are in service can be approved under approval series 160.035 (domestic only service) or 160.135 (SOLAS approved/international service). "035" boats are still in service, and can remain in service as long as they are maintained in a serviceable condition. These boats are no longer being manufactured and the regulations that governed their construction (46 CFR 160.035) were removed in the 2012 annual edition of the CFR. All current CG-Approved lifeboats are being built as "135" SOLAS boats under the provisions of 46 CFR 160.135.

For 160.035 lifeboats, a 2011 (or earlier) edition of 46 CFR 160 is needed for reference; for 160.135 lifeboats, 2012 (or later) editions of 46 CFR can be utilized. Annual editions of the CFR can be downloaded from gpo.gov/fdsys.

46 CFR 160.035 did not include equipment requirements for the lifeboats, as this was handled by the respective subchapter that the vessel (or facility) was inspected under (e.g. 33 CFR Subchaper N, 46 CFR Subchapters, I, I-A, W, etc.), based on the type of vessel/facility and the service and 'route' of that vessel. 46 CFR 160.135 incorporates the Life-Saving Appliances (LSA) Code, 2010 edition, by reference and the LSA does include the equipment list, as SOLAS boats are all intended for the same type of service. While the equipment requirements in 33 CFR 144.01-15 plainly apply to "035" boats, they also apply to the "135" boats as a CG approved deviation from the equipment carriage requirements incorporated by reference through 46 CFR 160.135.

The regulations in 33 CFR 144 haven't seen many changes from the original publishing in 1956 (and the equipment list still reads the same), but the 'intent' is that lifeboats on Fixed Platforms are an alternative to the primary lifesaving appliances, lifefloats, and minimal equipment is therefore allowed.

Heli-decks that are converted into work decks no longer meet the exemptions afforded by 33 CFR 143.110(b) and must meet the intent of §143.110(a) while being utilized as a work deck/work area.

Converting a heli-deck to a work deck may occur as part of a maintenance project (a typical example is on smaller platforms where the wellheads are accessed through the heli-deck) and is often a temporary arrangement. As such rails on these converted heli-decks may be of a temporary nature (e.g. constructed from scaffolding pieces as in typical offshore construction projects), as long as the temporary railing meets the intent and protection of the §143.110(a) requirements (heights, courses and securely fastened). The entire heli-deck does NOT need to be railed if the rail arrangement provides protection to personnel for the area/portion of the heli-deck that is being utilize as a work deck.

BSEE inspectors are verifying work deck railing arrangements in accordance with Z-PINCs 135 and 140.

Support Vessel FAQs

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Yes. As per the General Definitions of 46 U.S.C. Section 2101, an "Offshore Supply Vessel" is defined as a "motor vessel that regularly carries goods, supplies, individuals in addition to the crew, or equipment in support of exploration, exploitation, or production of offshore mineral or energy resources."

“Energy resources” does include wind energy. Therefore, self-propelled vessels that support wind energy do meet the definition of an OSV as defined in 46 U.S.C. Section 2101, because they comply with the three statutory requirements:
   1) they are motor vessels;
   2) they carry goods, supplies, individuals in addition to the crew, and/or equipment; and
   3) they support the exploration, exploitation, or production of energy resources.

Any vessel engaged in an OCS activity is subject to inspection in accordance with 33 CFR Subchapter N, Part 140, Subpart B.

An "OCS activity means any offshore activity associated with exploration for, or development or production of, the minerals of the Outer Continental Shelf" as defined in 33 CFR 140.10. The definition is broad and includes a whole host of activities beyond drilling and production type activities (i.e. seismic survey, construction, subsea construction, and well intervention, to name just a few). The key is that the activity must be related to exploration or the ultimate production of mineral resources on the OCS. Note: Energy resources beyond minerals (i.e. wind) are not included in the definition of an OCS activity regulated under Subchapter N, but are included in the in the definition of Offshore Supply Vessels that are U.S. Flagged and regulated under 46 CFR Subchapter I or L (see definitions at 46 CFR 90.10-40 and §125.160, respectively).

A "Unit means any OCS facility, vessel, rig, platform, or other vehicle or structure, domestic or foreign" per 33 CFR 140.10.

The inspection requirements for "vessels" (also defined in 33 CFR 140.10) engaged in OCS activities are listed at 33 CFR 140.101(a) and (c) through (e). §140.101(c) provides for announced and unannounced inspections that may be directed by the Officer in Charge, Marine Inspection (OCMI) to determine if units engaged in OCS activities are in compliance with the applicable requirements of Subchapter N. §140.101(d) lists what may comprise the inspection and §140.101(e) stipulates the recognition of valid international certificates issued to foreign units for matters covered by the certificates, unless there are clear grounds to believe that the unit or its equipment do not meet the particulars of the certificate.

U.S. flagged vessels (other than MODUs) have not typically been inspected under the provisions of 33 CFR Subchapter N due to the routine inspections of those vessels under the Subchapter(s) of 46 CFR that apply to the particular vessel (i.e.46 CFR Subchapters I, L and T), with the exception of 33 CFR Part 143, Subpart E for "standby vessels" (also defined in 33 CFR 140.10).

Foreign flagged vessels (other than MODUs and production units) have also not typically been involved in direct inspections offshore, although the provisions of 33 CFR 140.101(e) can be applied.

The parts of 33 CFR that apply to vessels engaged in an OCS activity (other than MODUs or production units/facilities) are as follows:
   • Part 140 - General (overarching requirements and procedures)
   • Part 141 - Personnel (citizenship requirements and exemptions)
   • Part 142 - Workplace Safety and Health
   • Part 143 - Design and Equipment, Subpart D (all vessels) and Subpart E (U.S. Flagged standby vessels)
   • Part 146 - Operations, Subpart D (casualty notifications) and Subpart E (notice of arrival)