Abstract: 1. An explosive assembly for producing an acoustic signature for minesweeg when detonated under water comprising a flexible line, explosive charges secured to said line at spaced points along the length of said line, the explosive content of said charges varying by increments from a minimum to a maximum at a substantially constant rate, the overall assembly having a weight-in-water so distributed that when the assembly is unrestrained in water the force of gravity places all segments of said line under tension, and means for firing said charges in rotation in the order of their ascending magnitude of explosive content, said charges being so spaced and distributed along said line that the combination of the spacing and the firing sequence renders said charges separate charges.