A marine cable cutter is provided for wirelessly severing wire responsive to an electromagnetic command signal. The cutter includes an explosive package for wrapping around the wire, and a clamshell case for containing the package around the wire. The package includes a wireless receiver to receive the command signal, an electric pulse generator triggered by the receiver, an explosive initiated by the generator, and a platform for containing the receiver, generator and explosive. The clamshell case includes a pair of envelopes connected along mutual first edges by a hinge and mutual second edges by respective clamps. The envelopes pivot on the hinge to open and receive the package with disposal of the wire therein, and subsequently to close and secure by the clamps. The envelopes can be composed of sheet metal with the clamps being flanges with aligned holes for receiving bolt fasteners.