Abstract: A bi-planar pontoon paravane is towed by a marine vessel and controls the depth and position of a towed seismic source array. The bi-planar pontoon paravane is made up of a buoyant bridge with right and left wings attached to the long sides of the bridge, the wings projecting into the water and, in concert, providing a side force. The paravane is towed by a tow line connected to an adjustable bridle which in turn is connected to the paravane. Remote adjustment of the bridle is provided by an hydraulic valve on the vessel controlling an hydraulic motor and gear arrangement on the paravane to adjust the bridle. Adjustment of the bridle adjusts the angle of attack of the paravane. The paravane provides a housing formed below the bridge and between the two wings for housing the seismic source array. A boom on the vessel is attached to the seismic source array, through the bridge, when the assembly is to be placed in or removed from the water.

Abstract: Disclosed is an improved air gun construction which lends itself to use with a plurality or array of similarly improved air guns which enables easy synchronization and timing of such array of air guns relative to one another. In the preferred embodiment, the air gun comprises a shuttle having magnetic properties and an electrical coil in proximity to said shuttle. When the air gun is actuated and the shuttle is accelerated, a voltage is induced in the coil by the flux lines from the magnetized shuttle moving through the turns of the coil. Electrical circuit means associated with each gun senses when a predetermined voltage is induced in the coil and generates a timing signal for each air gun. Additional electrical circuit means phases each of the timing signals from the air guns to occur at a predetermined time to thereby insure firing each of the air guns accurately.