Many boats have lateral ducts at the side. Noise from the engine room comes directly from these ducts to outside. This is not pleasant for boats moored next to you.

There are two possibilities to address that noise. These can combined together for the best result.

Applying a labyrinth:

 Often a labyrinth is already made behind the duct in order to avoid the water coming in. To absorb the noise you can cover the inside of the labyrinth with Acusticab. Make sure that sufficient air comes in and is carried out.

In suction ducts where there is no labyrinth, you can try to make one yourself

Depending on the situation, an Inno can also be applied with a round duct.