Has two vanes used to keep it away from the side of the ship, so that the cable runs laterally, making the sweep for mines. The towing cable would either snap the mine's anchor, making it rise to the surface where it could be destroyed, or snap on the anchor, making the paravane collide with the mine and so set it off harmlessly. Developed by the British navy during WWI. Coined from Greek root para- in the sense of alongside (as in parallel), + the vanes that keep it there, from Old English fana, originally meaning flag (migration of sense began with the vanes of windmills).
Some large warships were routinely equipped with paravane sweeps near the bows in case they inadvertently sailed into minefields.