A device which is deployable in the ocean environment to defeat an active torpedo comprises a mesh net structure constructed of a plurality of flat ribbons oriented in a particular geometric orientation with uniform spacings between adjacent ribbons, the ribbons being comprised of synthetic materials and more particularly of SPECTRA yarns in combination with yarns taken from the group comprising nylon, polyester, aramid, and KEVLAR. The net structure has stitched interconnections of the ribbons and a diameter of at least ten feet and exhibits a packing density of about 45 lbs/ft.sup.3 and a substantial neutral buoyancy in salt water.