A seismic streamer includes a jacket covering an exterior of the streamer. At least one strength member extends along the length of the jacket. The strength member is disposed inside the jacket. At least one seismic sensor is disposed in an interior of the jacket. A plurality of spacers is disposed at spaced apart positions along the strength member. An acoustically transparent material fills void space in the interior of the jacket. At least one structural parameter is selected to minimize pressure variations in the material resulting from axial elongation of the streamer under tension.