Abstract: A sleeve for a seismic air gun exhaust chamber is disclosed. The sleeve prevents water from accumulating in the air gun exhaust chamber when the air gun is vertically positioned and provides a convenient method for regulating the volume of the air gun exhaust chamber, and thus the frequency of acoustic energy emitted by the gun. The sleeve is characterized by a false bottom which is connected to the main chamber by an orifice and passages.

Abstract: An apparatus for positioning a plurality of marine seismic sources in an array. The marine seismic sources are retained in retaining means which are mounted to a frame so that each source is separated from the nearest other source in the array by a predetermined distance. Shock absorbing means are mounted in the frame intermediate each of the retaining means and each other retaining means mounted to the frame.

Abstract: A remotely controllable tail buoy for use in marine geophysical prospecting operations is disclosed. The tail buoy is attached to the trailing end of one or more seismic streamers towed by the vessel. The tail buoy is provided with rudders that are controlled by a steering mechanism and communication system. The communication system collects and processes radio signals emitted from a radio transmitter located on the towing vessel. The processed signals control the steering mechanism which includes a hydraulic pump for directing fluid into a hydraulic cylinder. The fluid flow rotates the rudders. The tail buoy will travel toward the direction that the rudders are turned and thus avoid hooking or entangling of the tail buoy on other like tail buoys or structures.

Abstract: An apparatus and method for generating a shock wave in water comprising a housing capable of containing compressed gas, attachment means fastened to the housing by which the apparatus is oriented in a selected positioned and exhaust means in the housing positioned to release compressed gas in directions other than substantially upward. In a preferred embodiment, a commercially available compressed air gun is modified by blinding off the uppermost exhaust ports.

Abstract: The invention is a multi-port, multi-chamber, tuned, air-powered subsea seismic source. It is suitable for producing a seismic wave in a subsea environment during seismic prospecting. Interconnected pressurized chambers are formed between plates located on a movable shuttle and cylinder walls extending inward from the source housing. The source is fired by moving the shuttle through a stroke and allowing the pressurized air within the air chambers to exit through ports into the surrounding water. A unique seal arrangement in also shown.