Policy and Guidance - Mobile Offshore Drilling Unit (MODU)

COMDTINST 16000.76, Marine Safety: OCS Inspections (previously Section G of the Marine Safety Manual, Volume II)

The following chapters of COMDTINST 16000.76, Marine Safety: Outer Continental Shelf Inspections are applicable to MODUs:

• Chapter 1, Regulations, Policy and Guidance for a Unit Conducting an OCS Activity,
• Chapter 2, Procedures Applicable to U.S. MODUs, and
• Chapter 3, Procedures Applicable to Foreign MODUs.

This Commandant Instruction replaced Marine Safety Manual (MSM), Volume II: Section G - OCS Activities (cancelled 20Sep2021 and listed here for historical reference only). Note that there was no content change with the republishing of MSM Vol II Section G as a separate Commandant Instruction on 20Sep2021, but future content revisions are planned.

Overview of U.S. and Foreign Flagged inspection/examination requirements

U.S. Flagged MODUs are inspected to applicable portions of 33 CFR Subchapter N (Outer Continental Shelf Activities) and 46 CFR Subchapters I-A (Mobile Offshore Drilling Units), F (Marine Engineering), J (Electrical Engineering) & S (Subdivision and Stability). Note that additional portions of 33 CFR relating to Navigation and Pollution and 46 CFR relating to licensing/manning, lifesaving/firefighting type approvals and dangerous cargoes also apply.

Foreign-Flagged MODUs engaged in OCS activities must comply with one-of-three 'options' for "Design and Equipment" (see 33 CFR 143.207(a), (b) and (c)) AND one-of-three 'options' for "Operations" (see 33 CFR 146.205(a), (b) and (c)). Additional details related to these examination options and applicable regulatory cites are available by clicking on the following links (opens a pdf in a separate window):

  ○  Option A MODUs - examined to specific parts of the U.S. MODU regulations

  ○  Option B MODUs - PANAMA (Flag State equivalency)

  ○  Option B MODUs - MARSHALL ISLANDS (Flag State equivalency)

  ○  Option C MODUs - examined to the MODU Code, 1979

  ○  Option C MODUs - examined to the 1989 & 2009 MODU Codes (note that 33 CFR 143.207(c) and §146.205(c) both reference the Code for Construction and Equipment of Mobile Offshore Drilling Units (1979 MODU Code), but the 1989 and 2009 MODU Codes have been accepted as equivalencies under this examination option)

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Code of Federal Regulations (CFRs)

CFRs that pertain to MODUs are as follows:

Primary subchapters -
  ○  33 CFR Subchapter N - Outer Continental Shelf Activities
  ○  46 CFR Subchapter I-A  - Mobile Offshore Drilling Units

Additional subchapters that apply (not all will apply to each of the MODUs inspected or examined under the subchapters listed above) -
  ○  46 CFR Subchapter A - Procedures Applicable to the Public
  ○  46 CFR Subchapter B - Merchant Marine Officers and Seamen
  ○  46 CFR Subchapter E - Load Lines
  ○  46 CFR Subchapter F - Marine Engineering
  ○  46 CFR Subchapter G - Documentation and Measurement of Vessels
  ○  46 CFR Subchapter J - Electrical Engineering
  ○  46 CFR Subchapter Q - Equipment, Construction and Materials: Specifications and Approval
  ○  46 CFR Subchapter S - Subdivision and Stability

Note that 46 CFR Subchapters N, O, or V, or portions thereof, may also be utilized for vessels with specific arrangements/equipment or involved in specific operations.

  ○  33 CFR Subchapter D - International Navigation Rules
  ○  33 CFR Subchapter E - Inland Navigation Rules
  ○  33 CFR Subchapter F - Vessel Operating Regulations
  ○  33 CFR Subchapter H - Maritime Security (Parts 101, 103 and 104)
  ○  33 CFR Subchapter O - Pollution
  ○  33 CFR Subchapter P - Ports and Waterways Safety

Also note that 33 CFR Subchapter A also has applicability in regards to administration and legal actions.

CFRs can be viewed at ecfr.gov (regularly updated online version) or govinfo.gov (annual editions).

National Policy

National policy letters that apply to MODUs are listed in the table below, grouped by issuing authority and ordered from newest to oldest (by policy number/original issue date). Click on the policy number to open the document (opens in a new window).

District Eight Policy

D8 policy letters that apply to MODUs are listed in the table below, grouped by issuing authority and ordered from newest to oldest (by policy number/original issue date). Click on the policy number to open the document (opens in a new window).

Note that policy letter numbers for all policies listed from 1999 and earlier do NOT have a policy number referenced on the letter itself, but the policy number listed was assigned by D8 for tracking purposes.

Navigation and Vessel Inspection Circulars (NVICs)

NVICs that apply to MODUs are listed in the table below, ordered from newest to oldest (by NVIC number). Click on the NVIC number to open the document (opens in a new window). ALL NVICs can be found on the Official NVIC Page.

MMS Work Instructions

Mission Management System (MMS) Work Instructions (WIs) that apply to mobile offshore drilling units (MODUs) are listed in the table below, grouped by issuing authority and ordered numerically by instruction number. All CVC MMS WIs can be viewed and accessed through the CG-CVC MMS page on their site. Click on the policy number to open the document (opens in a new window).

Marine Safety Information Bulletins (MSIBs)

MSIBs that apply to MODUs are listed in the table below, grouped by issuing authority and ordered from newest to oldest (by MSIB number/original issue date). Click on the MSIB number to open the document (opens in a new window).

Additional MSIBs issued by USCG Headquarters offices can be found here.

Codes for the Construction and Equipment of Mobile Offshore Drilling Units (MODU Codes)

This page contains electronic versions (pdf) of all three MODU Codes, as amended, and the resolutions that implemented and amended the Codes. The electronic MODU Codes were assembled by the OCSNCOE from publicly-available IMO Resolutions and have been annotated by the OCSNCOE to assist with understanding the amendments and their applicability. Click on the document name or resolution number to open the document (opens in a new window).

For additional information related to the MODU Codes, please see Drill Down Issue #20.

The documents in the table above consist of the Assembly resolutions creating each Code and the corrigenda and resolutions amending each Code as summarized below. Click on the resolution number to open the document (opens in a new window).

MODU Applicability Flowchart

For a pdf of the applicability flowchart displayed below, click here.

Inspection Job Aids

The following Job Aids pertain to Mobile Offshore Drilling Units working on the U.S. Outer Continental Shelf. Job Aids replaced the replaced the legacy CG-840 Books and can be a valuable tool for owners and operators to maintain regulatory compliance on their units.

• Mobile Offshore Drilling Unit (MODU) Job Aids:
  • U.S. Flag & Foreign Flagged "Option A": standard format or booklet.
  • Foreign Flagged "Option C": standard format or booklet.

Notes:

Job Aids are developed for use by the CG Marine Inspector, following internal CG procedures, and are provided as a convenience (and transparency) to industry. The Pre-Inspection/Pre-Exam and Follow-Up sections mainly pertain to administrative tasks of the Marine Inspector. While "if applicable" is NOT annotated within the Job Aid, there are inspection/exam items listed that may not apply to a particular unit.

Additional Job Aids and Marine Inspector Performance Qualification Standards (PQS) are available on CVC's MI Resources page.