There is provided a casing for a towable sonar apparatus, comprising: a tubular member, wherein the tubular member comprises a foam member or a mesh member; a first layer around the tubular member, wherein the first layer is porous.

A sensor streamer stretch section. At least some of the example embodiments are methods including measuring at least one parameter related to noise while towing the sensor streamer through a body of water with a towing vessel, and adjusting at least one of a spring constant and a damping coefficient of a stretch section disposed proximate the sensor streamer such that the measured parameter is minimized.

Method and apparatus for suppressing cable dynamics in a device towed in water. The apparatus includes at least one section for suppression of motion, wherein the at least one section includes an axial motion suppression section; and the axial motion suppression section comprising equipment for the attenuation of axial vibrations in an electro-mechanical cable. The equipment is configured to produce a digressive stiffness curve.

A downhole seismic array is disclosed. The array comprises a load-bearing cable for carrying a series of seismic sensor units arranged along its length. Each seismic sensor unit is attached to the load-bearing cable via a vibration-absorbing material and has a magnet to attach the seismic sensor unit to the well casing.

Method and dynamic vibration absorber device for reducing a resonant frequency of a node to which the dynamic vibration absorber device is attached to. The dynamic vibration absorber device includes a housing configured to be attached to the node; an absorber mass located inside the housing; and first and second diaphragms attached to the housing and configured to suspend the absorber mass inside the housing. The dynamic vibration absorber device changes a resonant frequency of the node to two smaller vibration peaks.

A downhole seismic array is disclosed. The array comprises a load-bearing cable for carrying a series of seismic sensor units arranged along its length. Each seismic sensor unit is attached to the load-bearing cable via a vibration-absorbing material and has a magnet to attach the seismic sensor unit to the well casing.

Method and apparatus for mitigating vibrations in a device towed in water. The apparatus includes one or more tuned elastic sections having a complex spring rate and adapted to attenuate vibrations in a specified frequency range; and a head end coupler adapted to couple the apparatus for vibration mitigation to a component of an electro-mechanical cable or a tow assembly. One of the one or more tuned elastic sections is coupled to the head end coupler with a high impedance material interface.

Method and dynamic vibration absorber device for reducing a resonant frequency of a node to which the dynamic vibration absorber device is attached to. The dynamic vibration absorber device includes a housing configured to be attached to the node; an absorber mass located inside the housing; and first and second diaphragms attached to the housing and configured to suspend the absorber mass inside the housing. The dynamic vibration absorber device changes a resonant frequency of the node to two smaller vibration peaks.