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US Coast Guard release Policy Letter to state they will not enforce IMO tier III regs for sub-500GT superyachts

Published on: 03 February 2021

US coast guard release Policy Letter to state they will not enforce IMO tier III regs for sub 500GT superyachts.

Following on from the last International Maritime Organisation (IMO) Marine Environment Protection Committee (MEPC) meeting where several members spoke in favour of a delay to the implementation or the enforcement of the Tier III regulations for over 24m but sub-500GT yachts, the US Coast Guard has released a letter stating their intentions for non-enforcement. 

This follows years of work from British Marine, ICOMIA and other national bodies to show that the technology and availability of the tier III engines for this range of large yacht still is not at the stage to allow the emission regulations to be enforced.
The policy letter is applicable for U.S-flagged or foreign-flagged large recreational vessels from 1 January 2021 until 31 December 2023 and permits operation of marine engines within US ECA’s without future U.S. Coast Guard (USCG) enforcement action even though the engines do not meet the MARPOL Annex VI Regulation 13 Tier III NOx emission standard.
The letter states that:


This policy letter outlines how the USCG will enforce reference (a), the Tier III NOx limits, for certain engines installed on recreational vessels above 24 meters in length and less than 500 gross tonnage (“large recreational vessels”). 
Officers in Charge, Marine Inspection (OCMI), affected Companies, and Recognised Organisations (RO) that issue International Air Pollution Prevention (IAPP) certificates on behalf of the United States are encouraged to apply this Policy Letter as it relates to the certification of qualifying engines (engines of 130 – 600 kW) that are required to meet International Maritime Organization (IMO) Tier III performance standards and their installation on large recreational vessels. This policy letter expires on December 31, 2023.
a. The USCG will defer enforcement on the operation of engines on large recreational vessels subject to the prohibition set out in reference (a). The deferral will be available after the temporary waiver for large recreational vessels set out in Regulation expires on January 1, 2021, until a suitable engine is available or December 31, 2023, whichever is earlier. This Policy Letter only applies to this Annex VI requirement and does not waive or otherwise affect the need to satisfy all applicable requirements of the U.S. Clean Air Act. 
b. Large recreational vessels constructed during the period of applicability of this policy letter, January 1, 2021 through December 31, 2023, will be permitted to operate engines within the U.S. portion of the ECAs without future USCG enforcement action even though the engines are not “MARPOL-compliant engines,” – that is, they do not meet the MARPOL Annex VI Regulation 13 Tier III NOx emission standard.
c. To identify as a qualifying large recreational vessel, any engine installed on a new or existing U.S-flagged or foreign-flagged large recreational vessel constructed before the necessary MARPOL-compliant engine is available or this Policy Letter expires must be: 
i. Properly certified to Clean Air Act Tier 3 emission standards (satisfied by having an EPA-issued Clean Air Act Tier 3 emission label affixed to each affected engine).
ii. Each affected engine must also be certified to MARPOL Tier II NOx standards. This requirement may be satisfied through proper documentation, including Technical Files and a Record Book of Engine Parameters, on board the vessel. 
iii. When installed on the large recreational vessel for which they are qualified, these qualifying engines will retain that status indefinitely; that is, they will be considered qualifying engines after MARPOL-compliant engines become available and will continue for the operating life of the engine. 
The letter also stipulates further parameters that the engines and certificates must still meet.
For further information on this and general enquiries for the applicability of IMO tier III emission regulations for large yachts, please contact the British Marine technical team via