On 01.01.2021 will enter into a force amended regulation 13 of MARPOL Annex VI.

According to new requirements in NOX Tier III emission control area, the operation of a marine diesel engine that is installed on a ship is allowed when the emission of nitrogen oxides (calculated as the total weighted emission of NO2) from the engine is within the limits of Tier III standard, when that ship is constructed on or after:

.1  1 January 2016 and is operating in the North American Emission Control Area or the United States Caribbean Sea Emission Control Area;

.2  1 January 2021 and is operating in the Baltic Sea Emission Control Area or the North Sea Emission Control Area;

and when that ship is operating in a NOX Tier III emission control area and is constructed on or after the date of adoption of such an emission control area.

The Tier and on/off status of marine diesel engines installed on board a ship to which Tier III requirements applies which are certified to both Tier II and Tier III or which are certified to Tier II only shall be recorded in a logbook or in an electronic record book at entry into and exit from a NOX Tier III emission control area, or when the on/off status changes within such an area, together with the date, time and position of the ship.

NOx emission levels (categories) as a function of Rated engine speed shows the figure below:

The Tier III requirements are applicable to all new build vessels (of gross tonnage 500 GT and above) with a length of ≥24 metres and sailing within a NOX Tier III emission control area with keel-laying on or after January 1st 2016 with an engine output of ≥130 kW.

 The Tier III requirement shall not apply to:

.1  a marine diesel engine installed on a ship with a length (L), as defined in regulation 1.19 of Annex I to MARPOL, of less than 24 metres when it has been specifically designed, and is used solely, for recreational purposes; or

.2  a marine diesel engine installed on a ship with a combined nameplate diesel engine propulsion power of less than 750 kW if it is demonstrated, to the satisfaction of the Administration, that the ship cannot comply with the Tier III standards because of design or construction limitations of the ship; or

.3  a marine diesel engine installed on a ship constructed prior to 1 January 2021 of less than 500 gross tonnage, with a length (L), as defined in regulation 1.19 of Annex I to MARPOL, of 24 metres or over when it has been specifically designed, and is used solely,
for recreational purposes.