A system including a plurality of elements of an elongate seismic streamer specifically for use in underwater seismic prospecting, an arrangement for interconnecting successive sections of the seismic streamer, whereby the number of recording traces corresponding to signals sensed by the seismic streamer can be doubled, and a plurality of data acquisition devices disposed in active boxes between adjacent sections, each acquisition device being provided with "2n" inputs and arranged to collect "2n" separate signals sensed by receivers of the sections of the seismic streamer, wherein the receivers of each element are divided into "n" pairs of receivers, and each receiver is connected through a line to both ends of the associated section, and wherein the arrangement includes first connection means for connecting the line associated with a first receiver of each pair, to an input of a first data acquisition device located at a first end of the section, and second connection means for connecting the lines associated with the second receiver of each pair to the line associated with the first receiver of said pair, so as to join them to a common input of the first acquisition device, the latter device then being operative to collect the signals supplied by all the receivers of two adjacent sections.