Why does mitigating underwater noise matter for shipowners?

Marine mammals and fish heavily rely on their sense of hearing for essential activities such as navigation, communication, and locating food sources. Each species exhibits sensitivity to specific frequency ranges within the spectrum, crucial for their survival and environmental interaction. However, the increasing underwater noise from ships is disrupting this balance, prompting regulators globally to develop regulations aimed at minimising its impact.

Regulatory frameworks

Since 2014, URN guidelines (MEPC.1/Circ.833, April 2014) have been available for commercial ships, offering non-mandatory advice for designers, builders, and operators. Covering design, operational, and maintenance considerations, these guidelines serve as a valuable resource for enhancing URN management practices.

Recently, new guidelines have been approved, providing additional insights into URN reduction approaches and technologies. During MEPC80, the IMO's Marine Environment Protection Committee adopted a revised strategy aimed at achieving net-zero greenhouse gas emissions by or around 2050, with discussions on underwater radiated noise (URN) and measures to reduce shipping’s impact on them (MEPC.1/Circ.906) and (MEPC.1/Circ.907).

While still non-mandatory, these guidelines offer detailed recommendations for both existing and new ships, emphasizing the importance of creating an Underwater Noise Management Plan. This plan is set to align with the mandatory Energy Efficiency Management Plan, ensuring a holistic approach to environmental sustainability.

States are implementing local restrictions, and an increasing number of speed reduction zones and Particularly Sensitive Sea Areas (PSSAs) are being established. Ports are also incentivizing compliance, with initiatives such as the Port of Vancouver offering significant fee discounts for vessels with LR's UWN-L notation.

Furthermore, the International Association of Classification Societies (IACS) is actively working towards Unified Standards for measurement, enhancing consistency and reliability across the industry.

Partner with LR advisory expertise

Stay ahead of the curve with our guidance on navigating these regulatory changes and optimizing your URN management strategies. Our experience in underwater noise measurement has been gained working closely with navies around the world to help them ensure that their vessels meet stringent noise guidelines. This has also provided us with direct access to 'one of a kind' proven facilities and equipment that we are now able to make available to commercial operators, too.

  • URN Management Plan Development
  • Vessel’s URN Predictions
  • Energy Efficiency & URN Relationships
  • Environmental Impact at Specific Locations
  • Field Measurements
  • Rotor-Hull Interaction
  • URN Mitigation Advisory
Fleet Benefits
  • Increased efficiency
  • Environmental protection
  • Decreased onboard noise level
  • Decreased material damage