A seismic streamer includes a jacket covering an exterior of the streamer, at least one strength member extending along the length of and disposed inside the jacket, at least one seismic sensor mounted in a sensor spacer affixed to the at least one strength member, and a void filler made from a material introduced into the jacket in liquid form and undergoing state change thereafter. The jacket includes an inner layer in contact with and having adhesiveness to the void filler, and an outer layer disposed over the outer layer and having substantially no adhesiveness.