Bubble curtain

Bubble curtains are used when working in water
to reduce propagation of shock waves (eg. acoustic waves from engines or pile driving, explotions etcetera),
and to reduce liquid or debris floating on the surface from spreading
to control the movements of fish
or for decoration and airing in aquariums.

The technique is based on bubbles of air (gas) being let out under the water surface, commonly on the bottom. When the bubbles rise they act as a barrier,a curtain, breaking the propagation of waves or the spreading of particles and other contaminants.

The technical systems basically consists of a compresor and pipe or hose with nozzles. When used to reduce acoustic waves from pile driving a distribution manifold made of plastic or rubber is commonly used.