Press Release

ClassNK Advises Existing Ships to Install Ballast Water Management Systems Early On (Updated in January 2021)

5 January 2021

Tokyo –Leading Classification Society ClassNK has been analyzing the retrofitting status of ballast water management systems (BWMS) on its registered ships periodically since 2018. The status has been updated based on the latest data and the Society has confirmed that installation deadlines based on the BWMS Convention for many of its registered ships are still concentrated in the year 2022.

As of the end of November 2020, 7,220 of the 9,159 ships registered with ClassNK are obligated to install BWMS in accordance with the BWM Convention. Among these, 3,982 ships have completed the installation, leaving 3,238 ships that still require attention. Although the number of ships without BWMS has decreased by 1,280 since August 2019, the installation deadline for these ships remains largely concentrated in 2022.

As difficulties are expected in the installation of BWMS if everyone around the world waits until 2022, ClassNK recommends installing well in advance. In addition, plan approval applications are also expected to concentrate during this period, therefore early application is strongly recommended. Please refer to the technical information TEC-1086 for the guidance on BWMS plan examinations.

TEC-1086 URL:

The latest information related to the BWM Convention and other technical information will be continuously provided through the ClassNK website (, with the latest information of the distribution of BWMS installation dates for ClassNK existing ships.

As of 30 Nov. 2020

As of 31 Aug. 2019 (reference)

As of 31 Aug. 2018 (reference)

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