Abstract: A control device (1) for controlling the position of a marine streamer comprising; an annular aerofoil (2), a mount (3) for mounting the annular aerofoil onto and around the streamer; and control means (4a, 4b) for controlling the tilt and/or rotation of the annular aerofoil (2) whereby to adjust the lateral position and/or depth of the streamer.

Abstract: A winglet for mounting on a trailing end of a flexible line to be towed by an underwater vehicle includes an internal collar member for connection to an inside surface of the line at the trailing end thereof, an outer collar member for connection to an outside surface of the line outboard of the internal collar, and connection means for fixing the internal and outer collar members to the line trailing end. A plurality of fins are mounted on an outside surface of the outer collar member and extend outwardly from the outer collar member.

Abstract: A deflector device for use with a tow line between a seismic survey vessel and a tow, in particular a streamer or streamer array, in the water behind the vessel comprises a vertically oriented wing-shaped body for producing a sideways force as it is towed through the water, and a towing bridle adapted to connect the wing-shaped body to the tow line. The bridle comprises first and second connecting elements connected between the tow line and respective longitudinally-spaced points along the high pressure side of the wing-shaped body. The wing-shaped body includes one or more buoyancy elements to render it slightly positively buoyant, and the length of at least one of the connecting elements is adjustable by remote contol in order to tilt the wing-shaped body. This gives the sideways force a vertical component, and so allows remote control of the depth of the deflector device, as well as its lateral offset from the vessel.

Abstract: A control device or “bird” for controlling the position of a marine seismic streamer is provided with an elongate, partly flexible body which is designed to be electrically and mechanically connected in series with a streamer. In its preferred form, the bird has two opposed wings which are independently controllable in order to control the streamer's lateral position as well as its depth.

Abstract: A method of deploying cable in a body of water comprising an autonomous underwater vehicle (AUV) capable of converting vertical motion into horizontal travel, and placing cable in the body of water with the AUV. The cable, usually a cable sensor array, is released from a cable storage section of the AUV as the AUV glides horizontally. Vertical motion can be provided by buoyancy change, by dropping the AUV into the water, or by release of the AUV from a weighted bunker at the bottom.

Abstract: A retriever is provided for a marine seismic cable or other tool. The retriever first comprises a housing. Disposed within the housing is a canister for containing gas under pressure. An inflatable bag is fluidly connected to the gas canister within the housing. Gas is prohibited from exiting the gas canister and inflating the bag until hydrostatic pressure acting upon the retriever exceeds a designated amount. If the cable sinks to a certain depth within a water body, the corresponding hydrostatic pressure acting upon the cable will exceed the preset pressure level. An actuating mechanism is then actuated, causing gas to exit the gas canister and to inflate the inflatable bag. In one arrangement, a pop-open cover is provided on the housing. As the bag inflates, it acts to release the pop-open cover from the housing and to further inflate outside of the housing of the retriever. The inflated bag will cause the cable to be buoyantly lifted to the surface of the water body.

Abstract: In a device for towing riders on or through the water it is known to have planar board(s) or wing(s). In this invention, there are two independently operated symmetrical wings hinged to wing supports. The fore mounted wing supports are secured to, and are perpendicular to, the longitudinal body of the craft which creates a front to rear axial line. The wings have hand hold openings through them at their trailing edge and are manually operated, up or down, by the slightly forward arms of a single prone rider who is aft of the wings. A belly board secured on top of the body of the craft and aft of wings, a knee brace perpendicular to the body of the craft and aft of the belly board, and a foot rest perpendicular to the body of the craft and aft of the knee brace; secures, and makes comfortable, the rider to the craft.

Abstract: A towed vehicle for positioning a towed device about a submarine, comprising: (a) a housing having a wing for providing lift when said housing is towed through water; (b) means coupled between said submarine and said housing for towing said housing; and (c) means coupled to said housing for varying the relative positions between the center of buoyancy and the center of gravity of said housing to dispose said wing in a given position.

Abstract: There is disclosed an improved sub-aqua device suitable for towing a person through the water. Specifically there is disclosed a sub-aqua device including: a support member; a pair of manoeuvring planes for manoeuvring the device, each defining an elevation plane; and a means for controlling each manoeuvring plane including a handle, each handle extending in a plane coincident with the respective elevation plane.

Abstract: The present invention relates generally a method and apparatus for adjusting the buoyancy of towed seismic arrays comprising a plurality of streamers and specifically to the dynamic buoyancy control of the buoyancy of a towed array of streamers by means of applying current to electroactive polymers (EAP) incorporated within the towed array of seismic streamers. The bulk density of the streamer array is electrically altered to accomplish neutral buoyancy for a towed array of streamers within the full range of water-densities from fresh to extremely dense seawater.

Abstract: A device for controlling the position of an underwater cable comprises a body, first and second actuators, and a pair of wings. The body is stationarily mountable to the underwater cable and the first and second actuators are disposed in the body. Each wing has an axis of rotation and the wings are coupled to the first and second actuators to control the depth and the horizontal position of the underwater cable in the water.

Abstract: Arcuate-winged submersible vehicles having improved hydrodynamic stability and maneuverability for use in, for example, underwater payload delivery and data acquisition. In one embodiment, a submersible vehicle includes a body having a pair of outwardly projecting at least partially arcuate wings, an adjustably positionable wing steering flap hingeably attached to each wing, at least one wing flap actuator coupled to the hull and to the wing steering flaps to controllably adjust the position of the wing steering flaps, an adjustably positionable hingeable tail steering flap attached to the hull, and at least one tail flap actuator coupled to the hull and to the tail steering flap to controllably adjust the position of the tail steering flap. The arcuate wings provide improved stability and maneuverability characteristics of the vehicle. In alternate embodiments, a vehicle may include arcuate wings having a swept leading edge or a swept trailing edge, or both.

Abstract: A method of controlling the lateral position of a towed body in water where the body is equipped with effectors for effecting at least aileron and rudder control. A lateral correction is defined by a distance measured perpendicular to the towed body's direction of travel. A first command indicative of an aileron control is determined that would cause the effectors to move the body laterally of the direction of travel by an amount equal to the lateral correction. A second command indicative of a rudder control is determined that would cause the effectors to move the body laterally of the direction of travel by an amount equal to the lateral correction. The first and second commands are combined to define a combined command that is applied to the effectors so that the optimum aileron and rudder controls are implemented simultaneously.

Abstract: Collapsible depth controller for mounting in relation to seismic cables or similar devices, comprising two wings, each being rotatably connected to a main body relative to a first axis of rotation perpendicular to the longitudinal direction of the depth controller, to be folded into an adapted room in the main body of the depth controller. The depth controller comprises a first motor for rotation of an at least partially cylindrically shaped cam plate or mushroom cam relative to its axis, the axis essentially corresponding to the longitudinal axis of the depth controller, said cam plate comprising at least one path or cam which along at least part of its length has an angular extension relative to the axis of the cam plate, at least one cam follower engaging into said cam plate and comprising a first coupling device for rotatable connection to the wings, where the first coupling device is positioned at a chosen distance from the first rotational axis of the wing.

Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. A cuff attached to an external device is in the form of a C-shaped cylindrical ring with a circular inner surface. A gap in the ring interrupts the inner surface. A throat is formed in the ring by the gap, which extends the full length of the cuff across the ends of the C. The spacing between the ends of the C across the throat defines the width of the gap. The width of the gap is slightly larger than the diameter of the cable so that the cuff can be slipped over the cable through the throat. The width of the gap is smaller than the diameter of the circular race so that, when the cuff is slid into position on the race, the cuff cannot be removed radially from the race. The inner surface of the cuff rides on the race to allow the cable to rotate inside the cuff.

Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. A cuff attached to an external device is in the form of a C-shaped cylindrical ring with a circular inner surface. A gap in the ring interrupts the inner surface. A throat is formed in the ring by the gap, which extends the full length of the cuff across the ends of the C. The spacing between the ends of the C across the throat defines the width of the gap. The width of the gap is slightly larger than the diameter of the cable so that the cuff can be slipped over the cable through the throat. The width of the gap is smaller than the diameter of the circular race so that, when the cuff is slid into position on the race, the cuff cannot be removed radially from the race. The inner surface of the cuff rides on the race to allow the cable to rotate inside the cuff.

Abstract: An attitude and roll stabilizer for towed undersea vehicles includes a vertical joining rod having an upper end and a lower end, a roll control weight mounted to the lower end of the vertical joining rod, an attitude control surface mounted to the upper end of the vertical joining rod, a tow rod pivotally mounted transverse to the vertical joining rod, an actuator member connected to the vertical joining rod between the tow rod and the roll control weight, and a connecting bar connecting the actuator adjacent to the aft end of the tow rod. A change in tow speed of the towed vehicle selectively pivots the tow rod about the vertical joining rod, and is correspondingly compensated for with a counteractive pitching of the attitude control surface and the roll control weight, thereby maintaining the level of the towed vehicle at the altered speed.

Abstract: An internal device for use in an underwater cable may comprise a body having an outer periphery, body being mountable inside the cable with the cable surrounding the outer periphery of the body. The body may include a cutaway portion, a slot, or a dovetail joint. An underwater cable arrangement may comprise an underwater cable and an internal device disposed in the cable with the cable surrounding the device. The underwater cable may include a stress member connected to the internal device by an interference fit or the internal device may include a slot for receiving the stress member. A method of connecting a stress member of an under water cable to an internal device includes forming an interference fit between a region of increased diameter of the stress member and the internal device.

Abstract: Arcuate-winged submersible vehicles having improved hydrodynamic stability and maneuverability for use in, for example, underwater payload delivery and data acquisition. In one embodiment, a submersible vehicle includes a body having a pair of outwardly projecting at least partially arcuate wings, an adjustably positionable wing steering flap hingeably attached to each wing, at least one wing flap actuator coupled to the hull and to the wing steering flaps to controllably adjust the position of the wing steering flaps, an adjustably positionable hingeable tail steering flap attached to the hull, and at least one tail flap actuator coupled to the hull and to the tail steering flap to controllably adjust the position of the tail steering flap. The arcuate wings provide improved stability and maneuverability characteristics of the vehicle. In alternate embodiments, a vehicle may include arcuate wings having a swept leading edge or a swept trailing edge, or both.

Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. A cuff attached to an external device is in the form of a C-shaped cylindrical ring with a circular inner surface. A gap in the ring interrupts the inner surface. A throat is formed in the ring by the gap, which extends the full length of the cuff across the ends of the C. The spacing between the ends of the C across the throat defines the width of the gap. The width of the gap is slightly larger than the diameter of the cable so that the cuff can be slipped over the cable through the throat. The width of the gap is smaller than the diameter of the circular race so that, when the cuff is slid into position on the race, the cuff cannot be removed radially from the race. The inner surface of the cuff rides on the race to allow the cable to rotate inside the cuff.

Abstract: A helical turbine assembly capable of providing high speed unidirectional rotation under a multidirectional ultra low-head fluid flow is disclosed. The assembly comprises an array of helical turbine units or modules arranged, vertically or horizontally, to harness, for example, water or wind power. Each turbine unit or module comprises a plurality of helical blades having an airfoil profile. The modules for wind power may be mounted to rotatable shafts supported by lightweight structures anchored by guy wires to the ground. The helical turbine can also provide ship propulsion by utilizing the power of ocean waves. In a further embodiment, a cylindrical distributor is provided in the helical turbine to channel the fluid flow to the blades of the turbine, thereby increasing efficiency and power output. The helical turbine with distributor may be used to lift or lower a body either being submerged into a fast stream or dragged in the fluid.

Abstract: A propelled cable fairing system for towing objects underwater having a plurality of cable fairings, which are individually propelled by motorized propulsion to avoid the thrust of propellers to overcome normally encountered drag heretofore utilized, which required use of longer and thicker cables resulting in a loss of control over the position of the towed object. In addition, the relative position of the propelled cable fairing system is maintained through a set of serially linked motor controllers that sense the relative position of each propelled cable fairing relative to it adjacent propelled cable fairing. Variation in position of the propelled cable fairing from a target, causes increase in speed of the motor or alters its angle of attack in order to keep the propelled cable fairings in predetermined alignment with the adjacent cable fairing.

Abstract: An underwater apparatus for performing subsurface operations adapted to be operated from a remote location above the surface of a body of water is disclosed. The apparatus includes a underwater vehicle that is made up of a tether management system connected to a detachable flying craft by a tether. The tether management system controls the amount of free tether between itself and the detachable flying craft. The detachable flying craft interfaces with various underwater structures. Also disclosed are methods of transferring power and/or data between two or more underwater devices using the underwater vehicle of the invention.

Abstract: Deflector device for lateral spreading of equipment being towed in water by a vessel, such as seismic exploration, fishing or mine sweeping. The device comprises at least one cylinder (35A-C) adapted to have its axis standing generally vertically in the water during towing. The cylinder or cylinders (35A-C) is/are rotatable and there is provided at least one motor for rotation of the cylinder or cylinders.

Abstract: Device for the adjustment of buoyancy of a seismic cable comprising a main part (1) adapted to firm, integrated mounting into a chosen point in the length of the cable, the main part (1) comprising fastening means (3,4) for one or more weight or buoyancy elements (2) and one or more exchangeable weight or buoyancy elements (2) adapted to being mounted into the main part (1).

Abstract: A depth control device for an underwater cable includes a rotary actuator having a rotating output shaft connected to a swash plate. Rotation of the swash plate by the actuator causes a rocker arm to pivot about an axis transverse to the axis of the output shaft. The rocker arm is drivingly connected to a drive shaft for rotating wings about their pitch axes. The pitch axes of the wings can be perpendicular to and intersecting the axis of the actuator output shaft, enabling the depth control device to be extremely compact.

Abstract: A device connected to an underwater cable by means of a sacrificial latch mechanism that breaks to protect the housing of the device from irreparable damage due to collisions with jetsam or other objects. The underwater device is connected to a cable having mounting elements disposed along its length. The device includes a housing and a latch body attached to the housing by a retainer, such as a set screw. A locking member extends from the latch body to engage the mounting element. A sacrificial element, such as a thin portion of the latch body or a frangible portion of the retainer, gives way in response to a predetermined force acting to separate the device from the cable before the force can damage the housing.

Abstract: A cluster of seismic streamer cable utility modules is provided with a set of hinged latching members. The hinged latching members are adapted secure the cluster to the steamer cable by closing the hinged latches around corresponding collars mounted on the streamer cable. The collars form an inner race while the closed hinged latches form an outer race to allow free relative rotation between the streamer cable and the cluster of modules.

Abstract: A towed buoy is deployed to a known depth below the surface from a submar and this depth is maintained by a control system that includes movable fins on the buoy. The movement of the buoy body and the buoy fins are monitored and used to evaluate sea state parameters, such as wave height for example. The tow cable is coupled to the buoy by means that permits measurement of the angle between the cable and the longitudinal axis of the buoy. Cable tension is also monitored to evaluate other surface parameters such as ocean current.

Abstract: A depth control apparatus for seismic streamers, comprising a central unit adapted for inserted mounting in the streamer substantially in axial alignment with the streamer, a housing which can rotate about the central unit and carries at least one control wing being angularly adjustable about a transverse axis adapted to be substantially horizontal in operative position, and an electric motor for adjusting the angle of the control wing about the transverse axis. The motor is located in the central unit and is adapted to have its current supply through the streamer. The control wing is so arranged on the housing that the transverse axis in operative position runs underneath the central unit. A transmission mechanism for the angular adjustment of the control wing by means of the motor, comprises a slide member which can be moved in the axial direction of the central unit and preferably surrounds the central unit.

Abstract: A vehicle towed by a submerged vehicle is surfaced with improved speed, rability and efficiency by displacing water from within the towed vehicle with gases evolved by electrolysis within the towed vehicle. Positive buoyancy is thus derived and the attitude of the towed vehicle is controllably altered so that hydrodynamic lift is also produced to rapidly surface the towed vehicle.

Abstract: A connector for attaching equipment to an underwater cable includes a cylindrical race having a plurality of sections pivotably connected by a hinge. The sections can pivot about the hinge to enable the race to be opened and detached from the cable. The hinge includes a plurality of sockets and a hinge pin received in the sockets. The hinge pin can preferably be retracted from the sockets to unlock the hinge and inserted into the sockets to lock the hinge. A retaining member may be provided to prevent the hinge pin from falling out of the sockets when the hinge pin is retracted.

Abstract: A connector for attaching equipment to an underwater cable includes a cylindrical race having a plurality of sections pivotably connected by a hinge. The sections can pivot about the hinge to enable the race to be opened and detached from the cable. The hinge includes a plurality of sockets and a hinge pin rotatably received in the sockets. The hinge pin can preferably be retracted from the sockets to unlock the hinge and inserted into the sockets to lock the hinge. A retaining member prevents the hinge pin from falling out of the sockets when the hinge pin is retracted.

Abstract: A rotary positioning module (RPM) for a paravane for use in connection with cable or hose towed from a towing platform through a towing medium. The RPM includes a stationary portion and a rotational portion, The stationary portion is adapted to be attached to the cable or hose, and includes a plurality of electrically-energizable field windings symmetrically positioned around the cable or hose, The rotational portion is rotatably mounted around the stationary portion for controlling orientation of rotary positioning module wings attached thereto as it is being towed through the towing medium to facilitate the positioning of the cable or hose in a towed array. The rotational portion includes a plurality of permanent magnets symmetrically positioned around the stationary portion in proximity to the field windings of the stationary portion and a rotary position sensor.

Abstract: A stern torpedo defense system uses a pair of passive sonar towed tactical etectors in tandem alignment to detect the presence and trajectory of a stern torpedo attack. The detectors are towed below the wake of a surface ship and include arcuate arrays of transducer elements mounted in low self-noise, roll pitch and yaw stabilized platforms. The region aft of the stern of the ship is examined by an overlapping plurality of preformed passive sonar beams of preselected beamwidth. Signal processing means monitor the power level of the beams and detect the presence and trajectory of an attacking torpedo so that suitable ordinance may timely and effectively be deployed to destroy the torpedo and thereby thwart the attack.

Abstract: A deflector (2) for installation in the tow-line (4, 5) between a towing vessel and a tow which is located in the water, e.g. a cable with seismic sources or a seismic source array, is suspended by a float (1) and has a fitting (9) therefrom having a tow-point (7) near the front part of the deflector connected to the tow-line (4), and an attachment point (8) to the rear of the deflector for further connection thereto of the rear part of the tow-line connected to the two. In order to be able to locate the deflector in a desired position in relation to the towing vessel and compensate for alternations in the effects of forces from the tow or vessel in addition to movements in the water, the tow-line (5) which leads on to the actual tow from the deflector body (2) is attached (8) to the deflector via a pivotable lever (10) which is situated at the same height as the lifting force center of the deflector body.

Abstract: A relatively short cable connects a surface vessel with an underwater vehe such that the cable does not assume a linear or straight path, but is instead provided with an arcuate shape to avoid snap loads in the cable. Floatation devices are secured to spaced locations on the cable to provide this non-linear cable configuration. The devices are balloons that exert restoring forces on the cable as required to avoid snap loads as the surface vessel heaves up and down due to wave action or the like.

Abstract: A minesweeping system, self-contained within the water vessel sought to be rotected against contact-actuated moored mines, effective against moored mines which are directly in the path of the vessel, featuring a beam-and-float arrangement. A ruddered float is maintained by a control system in virtually forward position with respect to the vessel and is attached at the fore end of a long boom beam, the aft end of which is pivotably attached to the bow of the vessel. A depressor for maintaining submergence of the lower end of the tow wire and the inward ends of the sweepwires is attached at the lower end of the tow wire, the upper end of which is attached to the beam near the float. Port and starboard sweepwires are attached to the tow wire near the depressor, each sweepwire projecting generally horizontally and backwardly obliquely. Diverters attached at the outward ends of the two sweepwires maintain their proper orientation. Cutters are situated along the outward ends of the sweepwires.

Abstract: For confidently coupling towed external devices to a marine seismic cable, a latch mechanism having a novel swing plate to improve the adjustability of the mechanism and provide a positive, clearly visible indication of latched and unlatched conditions. The swing plate serves as an external linkage between a rotatable adjustment head for a locking pin and a translatable lever arm for a locking rod. The locking pin and the locking rod extend from a latch housing on a towed device, such as a cable-leveling bird, and engage with a keyhole slot in a locking collar on the streamer. The swing plate engages the adjusting head, which protrudes from a side of the housing, in a push-nut engagement.

Abstract: An assembly capable of being launched from a submarine to carry into seawater an element responsive to a property of the water to be measured, comprising a carrier member coupled to the element, a lifting body shaped to provide hydrodynamic lift, a tether for mechanically connecting the lifting body to the submarine, the lifting body and the tether being constructed and arranged so that the lifting body, when connected to a moving submarine, will move through the water at a distance above the submarine, a supply of electrically conductive cable connected to the element and stored at least in part by the lifting body for payout to accommodate movement of the submarine relative to the member and releasable coupling means for holding the member and the lifting body together during their launch from the submarine and there after releasing the lifting body from the member.

Abstract: The invention provides a floatation apparatus for maintaining a longitudinal object at a constant depth below the water surface in a body of water. Several airtight chambers are connected in a serial connection to form a string of air tight chambers. A one-way check valve is installed in the chamber at one end of the string while the other end chamber is connected to a nose piece. Air is continuously supplied to the check valve connected to the end chamber. A separate one-way check valve is installed between each pair of adjacent chambers in the string in a manner that air can pass between only in the direction from the air source to the nose member. The floatation apparatus is pivotaly connected to the longitudinal object at more than one place by means of parallel links.

Abstract: An underwater diving plane has a main frame forming an isoceles triangle, having a base part, two side legs of equal length and an apex; a detachable transverse axle which is pivotally connected to the main frame, having two ends and two main planes each fixedly attached to the axle; a foreplane attached to the frame proximal to the apex; and a tow force transition cable to allow the planes stable planing action.

Abstract: In towing sources of seismic energy behind a vessel, especially in connection with seismic surveys in waters which are covered with ice, the buoyancy floats and also the sources of seismic energy are readily influenced by broken up ice collecting behind the icebreaking towing vessel. In order to stabilize the tow of sources of seismic energy a towing line (7) is secured between the buoyancy means (4) belonging to the tow of sources of energy (3) and the vessel (1) at a point (10) which is located in the area of the waterline, so that towing line (7) will extend in the area of the waterline. Another towing line (8) is connected directly with the array of sources of seismic energy (5) and is secured to a towing point (11) on the vessel (1) located below the waterline. An arrangement is also disclosed for securing the towing line (8) in a suitable location to avoid influence from ice and, furthermore, the design of floats (4) avoids influence from the ice.

Abstract: In seismic surveys at sea a system for maintaining the sources of seismic energy (2) at the same level when emitting their signals includes sensors (5) provided close to the sources of energy (2) for emitting signals representing pressure conditions and/or motion transmitted to a control unit (9). These signals are compared by control unit (9) for controlling driving devices (6) for the suspension lines (3) for the sources of seismic energy (2), so that their distances from the surface of the sea may be controlled to keep all sources (2) at the same level.

Abstract: An assembly capable of being launched from a submarine to carry into seawater an element responsive to a property of the water to be measured, comprising a carrier member coupled to the element, a lifting body shaped to provide hydrodynamic lift, a tether for mechanically connecting the lifting body to the submarine, the lifting body and the tether being constructed and arranged so that the lifting body, when connected to a moving submarine, will move through the water at a distance above the submarine, a supply of electrically conductive cable connected to the element and stored at least in part by the lifting body for payout to accommodate movement of the submarine relative to the member, and releasable coupling means for holding the member and the lifting body together during their launch from the submarine and thereafter releasing the lifting body from the member.

Abstract: The invention relates to an underwater cable cutting device which is used in combination with a geophysical exploration apparatus carrying a depth control unit. The depth control unit is provided with guiding planes which are protected by the cable cutting device mounted ahead of the depth control unit. The cutting device has a generally flat body having a curved forward portion and a pair of hook-shaped cutting portions on opposite rearwardly extending sides of the flat body for deflecting a cable from the depth control unit and severing the cable or mooring line with its cutting surface formed by the hooked-shaped cutting elements. The device is attached to an elongated housing and abuts a securing shank of the depth control unit, without requiring any modifications to be made to the depth control unit.

Abstract: A towline depressor (2) having forward and rearward ends with a main body portion (4) at the forward end. Wings (6) and (8) extend from the body with stabilizing fins (10) and (12) depending from the wings. A dorsal fin (14) having holes (16), (18) and (20) extends from the top center of the body for attaching the depressor to a towline. The holes permit attaching the towline at varying points relative to the center of gravity of the depressor.

Abstract: A depresser designed to keep a fish, towed by a ship, submerged comprises a flat swept wing joined to the towing cable by means of three suspenders making it possible to set it at an optimal angle of incidence. This enables a fish to be towed at a high speed which may go up to 30 knots while, at the same time, keeping it at a substantially constant depth of submersion.

Abstract: A mine neutralization system having self-propelled explosive charges fired t submarine mines by a mine detection and fire control system.

Abstract: An unmanned, self-propelled minesweeping apparatus, capable of sweeping at ubstantial depths, is described, comprising a torpedo-like submarine vehicle that deploys and tows a string of explosive mooring cable cutters terminating in a sea anchor. The sea anchor serves as a carrier for the cutters and the towline and, after ejection as a package from the vehicle, is actuated to an expanded condition and displaces the cutters and coils of towline therefrom.