Diesel Boats and Ships

Diesel boats and ships, which range in size and application from small recreational runabouts to large ocean-going vessels, are significant contributors to air pollution in many of our nation's cities and ports. Although marine diesel engines being produced today must meet relatively modest emission requirements, they continue to emit large amounts of nitrogen oxides (NOx) and particulate matter (PM), both of which contribute to serious public health problems.

In May 2004, as part of the Clean Air Nonroad Diesel Rule, EPA finalized new requirements for nonroad diesel fuel that will decrease the allowable levels of sulfur in fuel used in marine vessels by 99 percent. These fuel improvements will create immediate and significant environmental and public health benefits by reducing PM from existing engines.

At the same time, in a separate action, EPA announced its intent to propose more stringent emission standards for all new commercial, recreational, and auxiliary marine diesel engines except the very large engines used for propulsion on deep-sea vessels. These standards, which are modeled after the Clean Air Nonroad Diesel engines program, would require the use of advanced emission-control technologies similar to those already upcoming for heavy-duty diesel trucks and buses. The availability of clean nonroad diesel fuel required under our new nonroad fuel standards will enable the use of this technology on marine diesel engines. EPA estimates that NOx and PM emissions could be reduced by 90 percent by applying such advanced technology to these marine diesel engines.

This web site provides general and technical information on EPA's marine diesel engine rulemakings. Please note that emission standards for marine diesel engines under 37kW are included under our program for land-based nonroad diesel engines.

• Regulations/Guidance Documents
• Miscellaneous Documents
• Related EPA Pages
  

About PDF Files

Regulations/Guidance Documents

See the electronic CFR for the full text of current regulations that apply to marine diesel engines:

Marine diesel engines under 37 kW	40 CFR part 89
All other marine diesel engines	40 CFR part 94

Proposed Technical Amendments - Test Procedures for Testing Highway and Nonroad Engines and Omnibus Technical Amendments (published September 10, 2004)

• Fact Sheet: "Proposed Changes to Test Procedures for Nonroad Engines and Heavy-Duty Highway Engines" (EPA420-F-04-046, August 2004) 104K PDF (3 pages)
• Federal Register Notice: "Test Procedures for Testing Highway and Nonroad Engines and Omnibus Technical Amendments"
  • Entire Document 1.8M PDF (171 pages)
    • Part A: Pages 54845-54894 HTML or 292K PDF
    • Part B: Pages 54895-54944 HTML or 460K PDF
    • Part C: Pages 54945-54994 HTML or 772K PDF
    • Part D: Pages 54995-55015 HTML or 348K PDF
• Technical Support Document: "Test Procedures for Highway and Nonroad Engines and Omnibus Technical Amendments" (EPA420-D-04-004, August 2004) 808K PDF (70 pages)

Advance Notice of Proposed Rulemaking (ANPRM): Reducing Emissions for Locomotive and Marine Diesel Engines (Signed May 11, 2004)

• Federal Register Notice (Published June 29, 2004) HTML or 273K PDF (15 pages)
• Press Release: "New Clean Diesel Rule Major Step in a Decade of Progress" (May 11, 2004)
  
• Press Release: "Leavitt to Sign Clean Air Nonroad Diesel Rule" (May 10, 2004)
• Fact Sheet: "EPA's Program for Locomotives and Marine Diesel Engines" (EPA420-F-04-041, May 2004) 117K PDF (3 pages)
  
• Inventory Issues for Comment 45K PDF (3 pages)

Category 3 Marine Diesel Engines--Final Emission Standards (Published February 28, 2003)

• Federal Register Notice or 301K PDF (45 pages)
• Regulatory Announcement: "Emission Standards Adopted for New Marine Diesel Engines" (EPA420-F-03-001, January 2003) 428K PDF (7 pages)
  
• Summary and Analysis of Comments: "Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder" (EPA420-R-03-003, January 2003) 479K WPD or 377K PDF (121 pages)
• Final Regulatory Support Document: "Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder" (EPA420-R-03-004, January 2003) 1.3M WPD or 647K PDF (153 pages)
• Final index for Docket A-2001-11 186K WPD or 231K PDF (35 pages)

Final Rule for Recreational Marine Diesel Engines (published November 8, 2002)

• Fact Sheet:  "Emission Standards for New Nonroad Engines — Large Industrial Spark-ignition Engines, Recreational Marine Diesel Engines, and Recreational Vehicles" (EPA420-F-02-037, September 2002) 412K PDF (7 pages)
• Federal Register Notice (published November 8, 2002) 1.1M PDF (207 pages)
  
• Summary and Analysis of Comments (EPA420-R-02-023, September 2002) 427K ZIP WPD or 1.1M PDF (319 pages)
  
• Final Regulatory Support Document (EPA420-R-02-022, September 2002) 1.3M ZIP WPD or 2.6M PDF (687 pages)
  
  • Final Regulatory Support Document by Chapter
• Environmental Impacts of Newly Regulated Nonroad Engines (EPA420-F-02-033, September 2002) 24K PDF (5 pages)
  
• Frequently Asked Questions from Owners of Recreational Boats with Diesel Engines (EPA420-F-02-042, September 2002) 399K PDF (3 pages)
  
• Emission Factors for Recreational Marine Diesel Engines (EPA420-F-02-044, September 2002) 60K PDF (4 pages)
  
• How to Maintain or Rebuild Engines Certified to EPA Standards (EPA420-F-02-035, September 2002) 407K PDF (6 pages)
  
• Blue Sky Series Engines (EPA420-F-02-036, September 2002) 397K PDF (3 pages)
• Plain-Language Format of Emission Regulations for Nonroad Engines (EPA420-F-02-046, September 2002) 405K PDF (6 pages)
  
• Docket index (as of Sept. 13, 2002) 751K WPD or 690K PDF (141 pages)

  Other related documents regarding the final rule are available at www.epa.gov/otaq/regs/nonroad/2002/cleanrec-final.htm

Category 3 Marine Diesel Engines - Proposed Emission Standards (published May 29, 2002)

• Federal Register Notice 453K HTML or  365K PDF (62 pages)
• Fact Sheet: "Emission Standards for New Marine Diesel Engines" (EPA420-F-02-005, April 2002) 20K PDF (6 pages)
• Fact Sheet: "Emission Standards for New Marine Diesel Engines: Relationship Between EPA's Control Program and MARPOL Annex VI" (EPA420-F-02-004, April 2002) 16K PDF (6 pages)
• Draft Regulatory Support Document: "Control of Emissions from Compression-Ignition Marine Diesel Engines At or Above 30 Liters per Cylinder" (EPA420-D-02-002, April 2002) 309K ZIP WPD or 615K PDF
(160 pages)
• Docket index as of May 23, 2002  101K WPD or  89K PDF (24 pages)
• Settlement Agreement, January 18, 2001  170K PDF (7 pages)

Proposed Rule for Recreational Marine Diesel Engines (published October 5, 2001)

• Fact sheet: "Emission Standards for New Nonroad Engines"  (EPA420-F-01-026, September 2001)
• Federal Register Notice (published October 5, 2001)
• Draft Regulatory Support Document  (EPA420-D-01-004, September 2001)
  • Draft Regulatory Support Document by Chapter
• Frequently Asked Questions:  "Emission Standards for Recreational Marine Diesel Engines"  (EPA420-F-01-029, September 2001)
• Report of the Small Business Advocacy Review Panel on Emissions Standards for New Compression-ignition and Spark-ignition Recreational Marine Engines (EPA420-R-01-048, September 2001)

Advance Notice of Proposed Rulemaking - Control of Emissions from Nonroad Large Spark-Ignition Engines, Recreational Engines (Marine and Land-Based), and Highway Motorcycles (published December 7, 2000)

Final Rule - Emission Standards for Commercial Marine Diesel Engines (published December 29, 1999)

Proposed Rule - Emission Standards for Commercial Marine Diesel Engines (published December 11, 1998)

• Federal Register Notice HTML or 738K PDF

Advance Notice of Proposed Rulemaking - Emission Standards for Marine Diesel Engines (published May 22, 1998)

• Federal Register Notice HTML or 77K PDF

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Miscellaneous Documents

• "Overview of EPA's Emission Standards for Marine Engines" (EPA420-F-04-031, August 2004) 184K PDF (9 pages)
  
  
• Modeling Commercial Marine Emission Inventories
  EPA's current marine inventory guidance document (Procedures for Emission Inventory Preparation, Volume IV: Mobile Sources, EPA420-R-92-009, December 1992) uses modeling techniques based on fuel consumption that were common at that time. Since then, we have developed new marine inventory techniques as part of our rulemaking process for emission standards for commercial marine diesel engines. These techniques are more similar to the techniques we use for mobile sources generally, and rely on emission factors, population estimates, and usage characteristics. We are currently using these techniques to update our marine inventories and to develop marine components for our MOVES model. This new work will provide the foundation for a new marine inventory guidance document, including more research into emission factors, population, and operating characteristics. Until this work is completed, states and other stakeholders are encouraged to refer to the inventories we prepared for our commercial marine diesel engine standards for use in developing their own inventories. Chapter 7 of the Final Regulatory Support Document (EPA420-R-03-004, January 2003) for EPA's 2003 rule, "Control of Emissions from New Compression-Ignition Engines at or Above 30 Liters per Cylinder", contains our inventory estimates and a description of how those estimates were produced for Category 3 commercial marine vessels. Chapter 5 of the Final Regulatory Impact Analysis (EPA420-R-99-026, November 1999) for EPA's 1999 rule, "Control of Emissions from Marine Diesel Engines", contains our inventory estimates and a description of how those estimates were produced for Category 1 and 2 commercial marine vessels.
• Category 3 Marine Diesel Engines - Final Emission Standards Final Regulatory Support Document (EPA420-R-03-004, January 2003) 647K PDF (153 pages)
• "Final Regulatory Impact Analysis: Control of Emissions from Marine Diesel Engines" (EPA420-R-99-026, November 1999) 966K PDF (132 pages)
  
  
• "Analysis of Commercial Marine Vessels Emissions and Fuel Consumption Data"
  (EPA420-R-00-002, February 2000)  4M DOC or 2.6M PDF
  
  
• Commercial Marine Activity in the United States Final Reports 
  

• IMO MARPOL Annex VI

• "Nonroad Engine and Vehicle Emission Study Report" (Publication nos. EPA-21A-2001 or EPA460/3-91-002, November 1991)
  This "nonroad study" quantifies the contribution of nonroad sources to air pollution, including volatile organic compounds (VOCs), oxides of nitrogen (NOx), carbon monoxide (CO), and particulate matter (PM).  The study covers 10 equipment categories, including: lawn and garden equipment, farm and construction equipment, recreational vehicles, marine vessels, and airport service equipment.

Paper copies of this study are available from the National Technical Information Service (NTIS) - Publication #PB-92-126960.

Links to Related EPA Pages

• Nonroad Diesel Equipment (which includes marine diesel engines under 37kW)

• Gasoline Boats and Personal Watercraft

• Engine Certification Information Center

• Compliance Fees
• Marinas & Boating (from EPA Office of Water)
• Importing Vehicles and Engines

For further information or assistance regarding this Web page, please contact the ASD Information Line at (734) 214-4636 or email: asdinfo@epa.gov.