After a couple of years with no progress to report, the International Maritime Organization (IMO) appears to be nearing completion of “Voluntary Guidelines for the Reduction of Underwater Noise from Commercial Shipping.”  This process began in 2008 with a burst of activity and focus from the US and European IMO representatives, but appeared to languish in recent years (see this earlier AEInews report, with links to key documents).

The effort falls under the purview of the IMO’s Marine Environmental Protection Committee (MEPC), which assigned development of the standards to its sub-committee on Ship Design and Environment (DE).  The DE formed a “drafting group” led by the US, and this group has nearly completed its work, with just one paragraph in the preamble still to be solidified.  At its March 2013 meeting, the DE subcommittee approved the draft guidelines; their next step along the long and winding bureaucratic road will be their submission to the full MEPC at its next meeting, in April 2014.

The draft guidelines are currently not publicly available, but the DE meeting summary notes:

The non-mandatory Guidelines are intended to provide general advice about reduction of underwater noise to designers, shipbuilders and ship operators and consider common technologies and measures that may be relevant for most sectors of the commercial shipping industry. Designers, shipbuilders, and ship operators are encouraged to also consider technologies and operational measures not included in these Guidelines, which may be more appropriate for specific applications.

The guidelines give recommendations on predicting underwater noise levels, such as using underwater noise computational models; standards and references that may be used, including ISO/PAS 17208-1 “Acoustics – Quantities and procedures for description and measurement of underwater sound from ships – Part 1: General requirements for measurements in deep water” (see this ISO press release on these new standards); design considerations; onboard machinery selection and location; additional technologies for existing ships; and operational and maintenance considerations.

Here’s hoping that the MEPC is able to take up the Guidelines at their 2014 meeting as planned, completing this modest first step of encouraging the shipping industry to incorporate noise emissions into the design of new vessels.  The ISO/PAS standards will provide clear guidance for measuring the noise footprint of ships, though the IMO is not ready to suggest or mandate any particular maximum noise levels at this time. See this AEInews post on NOAA’s recent ocean noise mapping project; shipping noise is the predominant human contributor to overall ocean noise levels.