a disc shaped head 29a an elongate section of pipe 30 slidably retains the plunger the length of the plunger is such that it normally lies just short of a pin 31 which is held in shear between the inner end of pipe 30 and a short length of tubing 32 molded in primary float 26 when the glide body impacts on the bottom plunger head 29a is displaced and plunger 29 drives pin 31 from pipe 30 and into tubing 32 spring 27 ejects the primary float from the mouth of the cavity see fig5 with the primary float out of the way a semicylindrically shell shaped tray 33 is driven forward toward the mouth of the elongate body 18 by a plunger 34 and biasing spring 35 a shaft 36 connected to the plunger spring combination guides the combination 39 s extension toward the mouth of the elongate body driving the tray as it does a lanyard 37 coupled to the ejected primary float pulls out a secondary float 38 and both are buoyed upward a recess 38a in the secondary float contains a number of hydrophones 39 each coupled together by a conductor 41 the buoyed conductor in turn pulls a preamplifier 40 from the tray 33 and additional lengths of conductor 41 are unwound from a pair of spindles 42 conductors 41 are coupled inside the glide bodies to the sensor cables 17 after all the conductor has been pulled from the spindles the floats hydrophones and preamplifiers assume the configuration shown in fig2 while what has been disclosed above is a novel apparatus for deploying hydrophone arrays the inventive concept of this invention also embraces the method of deployment this method is schematically depicted in fig7 first there is.