405 comprise two individually insulated braided 16 awg copper wires the jacket 406 comprises a compressively biased vinyl sheath which serves to locate and compress the conductors 405 when the tether 401 is not under tension the combination of compressive loading in the conductors 405 and compliance in the jacket 406 serve as the equivalent of the low bulk modulus layers 102 203 and 303 seen in other embodiments in reducing the change in lay length of the conductors 405 through the change in length of the high strength core 402 over a range of tensions in some embodiments of the present invention as seen in fig5 a low drag lightweight electromechanical tether 501 is shown wherein the layers are of rectangular cross section in this embodiment the tether 501 which may have a length of 500 meters comprises a multi layered high strength core 502 each layer of high strength core 502 for example layer 510 may comprise a number of individual carbon fiber pultrusions of square or rectangular cross section which are designed to make the high strength core 502 have a smaller diameter than an equivalent high strength core built of cylindrical rods as the packing factor is higher compared to layers of cylindrical elements in some embodiments each carbon fiber pultrusion in the high strength core 502 is pultruded along a helical path to eliminate latent stresses when assembled into the tether 501 in one example each pultrusion has a major cross sectional dimension of between 3 and 5 millimeters as the helical angle of layer 510 is small the stresses in individual carbon.