The present invention is a submersible device comprising a body encasing an enclosed compressible void capable of physically responding to changes in ambient pressure imparted by the device's depth underwater. This physical response to pressure changes actuates a dynamic dive plane. The forces imparted on the dive plane by the motion of the device through the water drives the device to seek, achieve and then maintain a predetermined depth. This device can be used for fishing applications and other underwater activities that benefit from dynamic depth control.

A modular subsea fluid storage unit comprises a variable-volume inner tank having a rigid top panel and a peripheral wall that is flexible by virtue of concertina formations. The peripheral wall is extensible and retractable vertically while the horizontal width of the tank remains substantially unchanged. A side wall of a lower housing part surrounds and is spaced horizontally from the peripheral wall of the inner tank to define a floodable gap between the peripheral wall and the side wall that surrounds the tank. An upper housing part extends over and is vertically spaced from the top panel of the inner tank and overlaps the side wall to enclose the inner tank. The floodable gap and the upper housing part enhance thermal insulation and trap any fluids that may leak from the inner tank.

A modular subsea fluid storage unit comprises a variable-volume inner tank having a rigid top panel and a peripheral wall that is flexible by virtue of concertina formations. The peripheral wall is extensible and retractable vertically while the horizontal width of the tank remains substantially unchanged. A side wall of a lower housing part surrounds and is spaced horizontally from the peripheral wall of the inner tank to define a floodable gap between the peripheral wall and the side wall that surrounds the tank. An upper housing part extends over and is vertically spaced from the top panel of the inner tank and overlaps the side wall to enclose the inner tank. The floodable gap and the upper housing part enhance thermal insulation and trap any fluids that may leak from the inner tank.

The present invention relates to a marine structure comprising a launch and recovery system for a submersible vehicle, and methods of operating the marine structure. The system comprises: a docking receiver, a towing head comprising a locking mechanism and being connectable to the docking receiver (13), a towing arrangement adapted to mechanically connect the towing head to the marine structure and being adapted to control the distance between the towing head and the docking receiver, and a lifting device connected to the docking receiver and being adapted to move the docking receiver relative to the marine structure. The lifting device can arrange the docking receiver in a towing head receiving and/or releasing position in which the docking receiver: (i) is completely submerged into the body of water, and (ii) is prevented from moving relative to the marine structure.

The present invention relates to a marine structure comprising a launch and recovery system for a submersible vehicle, and methods of operating the marine structure. The system comprises: a docking receiver, a towing head comprising a locking mechanism and being connectable to the docking receiver (13), a towing arrangement adapted to mechanically connect the towing head to the marine structure and being adapted to control the distance between the towing head and the docking receiver, and a lifting device connected to the docking receiver and being adapted to move the docking receiver relative to the marine structure. The lifting device can arrange the docking receiver in a towing head receiving and/or releasing position in which the docking receiver: (i) is completely submerged into the body of water, and (ii) is prevented from moving relative to the marine structure.

A ribbon-foil depressor is incorporated into a towed seismic array to provide downward lift to array sections or components. The ribbon-foil depressors may be deployed on the port and starboard spur lines or on the outboard separation ropes. The ribbon-foil depressors may be used to submerge and operate seismic equipment at depths as low as 60 m or more and are capable of maintaining towed seismic streamer cables at these depths and still remain stable through various speed changes and turns.

A seismic apparatus includes one or more seismic cable systems configured to acquire seismic data, each seismic cable system having one or more of a cable jacket, a reservoir for a ballast fluid or other ballast medium, and an actuator or other transfer mechanism configured to transfer the ballast fluid between the reservoir and the seismic cable system during acquisition of the seismic data, e.g., where the ballast fluid is transferred to the seismic cable system within the cable jacket. A controller can be configured to adjust a buoyancy of the seismic cable system responsive to the transfer of the ballast fluid, e.g., where the internal volume expands or contract based on the fluid transfer.

A control system for a towed object (1, 6; 20; 30; 50) in or on a body of water comprise one or more towing members (3) extending between the object (1) and a towing vessel (2). One or more ballast members (4) are movably connected to a respective one of said one or more towing members (3) and controllably movable at least a distance along its respective towing member. The towed object (1) may be controlled by moving one or more ballast members (4) on a towing member (3) in order to control the catenary (c) of a towing member (3). Individual ballast members (4) may be manipulated individually in order to correct, preserve or otherwise change the geometry of a trawl.

A control system for a towed object (1, 6; 20; 30; 50) in or on a body of water comprise one or more towing members (3) extending between the object (1) and a towing vessel (2). One or more ballast members (4) are movably connected to a respective one of said one or more towing members (3) and controllably movable at least a distance along its respective towing member. The towed object (1) may be controlled by moving one or more ballast members (4) on a towing member (3) in order to control the catenary (c) of a towing member (3). Individual ballast members (4) may be manipulated individually in order to correct, preserve or otherwise change the geometry of a trawl.

A vehicle system may include a mother ship and an unmanned water vehicle that can be received on the mother ship. To recover the unmanned water vehicle, a floating body connected to the mother ship via a line can be lowered into water. A catch device for catching the line may be positioned on the unmanned water vehicle. The floating body may transmit location signals that can be received and used by the unmanned water vehicle to navigate towards the floating body. The unmanned water vehicle may be configured to circle the floating body, and the catch device of the unmanned water vehicle may then catch the line to create a connection between the mother ship and the unmanned water vehicle.”