Abstract: A fluidborne projector of sound derived from an electro-mechanical noise source translates acoustical energy through a piston subjected to balanced pressures of gas and liquid to enabled dynamic displacement thereof. Such displacement of the piston to a static position is regulated by controlled pressurization of gas, mechanically limited to prevent damage from changing pressures exerted on the piston.

Abstract: A mine sweeping system including deployable horizontal antennas to establ a detection and navigation grid extending underwater from a beach to a distance offshore. A computer-controlled transmitter unit having a waveform generator and amplifier, transmits signals to each antenna, at unique frequencies and phases for different spatial locations within the grid. An autonomous underwater vehicle having multi-integrated sensors detects anomalies in the electromagnetic field caused by both magnetic and non-magnetic objects therein during underwater travel utilizing the electromagnetic field as a navigational grid. The autonomous underwater vehicle also deposits mine-clearing explosives at each magnetic anomaly for detonation under command signal using the horizontal antennas which provide a means for establishing a navigation grid to permit landing craft and other vessels to navigate in the region cleared of mines.