Abstract: A foil system is used with a towed marine cable array to provide downward, upward or lateral lift to the array. The foil system can be coupled with the cable and configured to bias the submerged payload toward a target position. The foil system can include a group of foil sections each having a leading edge collectively defining an angle of attack, and a group of through-cables supporting the group of foil sections within the foil system. A subset of through-cables of the group of through-cables are arranged through front halves of the group of foil sections. This subset of through-cables can be selectively tensionable, and manipulatable to define a tensioned one of the subset of through-cables as being offset from a chord that is defined between the leading edge and a trailing edge of any of the foil sections. The foil system can thus induce one or more angles of attack for the group of foil sections, based on a rotational constraint defined by the tensioned one of the through-cables.

Abstract: A foil for a towed cable includes a body defining at least two conduits. The body has a foil shape having a leading edge and a trailing edge. The foil shape defines a first surface extending between the leading edge and the trailing edge configured to provide lift. The foil shape defines a second surface opposed to the first surface extending between the leading edge and the trailing edge. The foil shape defines first and second lateral sides that extend between respective lateral edges of the first and second surfaces, the leading edge, and the trailing edge. A first conduit is defined within the forward half of the body adjacent to the leading edge, is open to each of the first and second lateral sides, and is configured to receive a cable therethrough. A second conduit may be defined within the body and filled with buoyant material.

Abstract: Embodiments herein include a fairing for a marine seismic array system that includes a foil having a leading edge and a trailing edge and defining a chord length and a span length, a first interior conduit oriented along the span length aft of the leading edge, and a second interior conduit oriented along the span length forward of the trailing edge. The conduits are separated by a distance. A first cable having a first length extends within the first conduit and a second cable having a second length extends within the second conduit, and the fairing can rotate about the first cable within the first conduit.

Abstract: A marine array having various embodiments of a modular foil system is disclosed. The modular foil system may be configured to generate lift when towed in a marine environment, and thus used to move, position, and/or depress instrument of the array. The modular foil system may include multiple groups of foil sections, each having an angle of attack that is adjustable relative to other groups of foil sections. For example, each group may be supported by a pair of through cables, and an actuator may adjust a tension in one or both of through cables, thereby alerting the angle of attack. The pair of through cables may converge toward one another at connection points adjacent opposing ends of a given group of foil sections of the modular system. The connection points thus establishing a modular framework to couple the given group to other groups of foils of the system.

Abstract: A foil system is used with a towed marine cable array to provide downward, upward or lateral lift to the array. The foil system can be coupled with the cable and configured to bias the submerged payload toward a target position. The foil system can include a group of foil sections each having a leading edge collectively defining an angle of attack, and a group of through-cables supporting the group of foil sections within the foil system. A subset of through-cables of the group of through-cables are arranged through front halves of the group of foil sections. This subset of through-cables can be selectively tensionable, and manipulatable to define a tensioned one of the subset of through-cables as being offset from a chord that is defined between the leading edge and a trailing edge of any of the foil sections. The foil system can thus induce one or more angles of attack for the group of foil sections, based on a rotational constraint defined by the tensioned one of the through-cables.

Abstract: A marine array having various embodiments of a modular foil system is disclosed. The modular foil system may be configured to generate lift when towed in a marine environment, and thus used to move, position, and/or depress instrument of the array. The modular foil system may include multiple groups of foil sections, each having an angle of attack that is adjustable relative to other groups of foil sections. For example, each group may be supported by a pair of through cables, and an actuator may adjust a tension in one or both of through cables, thereby alerting the angle of attack. The pair of through cables may converge toward one another at connection points adjacent opposing ends of a given group of foil sections of the modular system. The connection points thus establishing a modular framework to couple the given group to other groups of foils of the system.

Abstract: A foil for a towed cable includes a body defining at least two conduits. The body has a foil shape having a leading edge and a trailing edge. The foil shape defines a first surface extending between the leading edge and the trailing edge configured to provide lift. The foil shape defines a second surface opposed to the first surface extending between the leading edge and the trailing edge. The foil shape defines first and second lateral sides that extend between respective lateral edges of the first and second surfaces, the leading edge, and the trailing edge. A first conduit is defined within the forward half of the body adjacent to the leading edge, is open to each of the first and second lateral sides, and is configured to receive a cable therethrough. A second conduit may be defined within the body and filled with buoyant material.

Abstract: 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.

Abstract: A foil having a leading edge, trailing edge, chord and span is attached between a first head float position and bottom submerged position below the head float on the array. The foil being flexible along its span and has a first interior conduit rearward of the leading edge and a second interior conduit forward of the trailing edge. The conduits are centered on the chord and separated by a distance. A first cable having a first length is strung inside the first conduit and a second cable having a second length is strung inside the second conduit, and an adjustment mechanism is used to vary the length of the first cable relative to the length of the second cable and vice versa.

Abstract: A foil having a leading edge, trailing edge, chord and span is attached between a first head float position and bottom submerged position below the head float on the array. The foil being flexible along its span and has a first interior conduit rearward of the leading edge and a second interior conduit forward of the trailing edge. The conduits are centered on the chord and separated by a distance. A first cable having a first length is strung inside the first conduit and a second cable having a second length is strung inside the second conduit, and an adjustment mechanism is used to vary the length of the first cable relative to the length of the second cable and vice versa.

Abstract: A commercial fishing trawl has a net and a mouth opening defined by a head line, a foot line, and side lines. The mouth opening is spread by a plurality of foil segments threaded on one or more of the head line, foot line, or side lines. Foil segments may also be threaded on tag lines or foil lines attached about the mouth opening to spread and maintain the mouth opening as the trawl is towed through the water, behind a tow vessel.

Abstract: A foil having a leading edge, trailing edge, chord and span is attached between a first head float position and bottom submerged position below the head float on the array. The foil being flexible along its span and has a first interior conduit rearward of the leading edge and a second interior conduit forward of the trailing edge. The conduits are centered on the chord and separated by a distance. A first cable having a first length is strung inside the first conduit and a second cable having a second length is strung inside the second conduit, and an adjustment mechanism is used to vary the length of the first cable relative to the length of the second cable and vice versa.

Abstract: A segmented-foil divertor for marine towed application, such as marine seismic exploration, having a plurality of longitudinally stackable foil segments with an internal conduit extending along the span of each segment to receive a cable passing therethrough.

Abstract: 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.

Abstract: A foil having a leading edge, trailing edge, chord and span is attached between a first head float position and bottom submerged position below the head float on the array. The foil being flexible along its span and has a first interior conduit rearward of the leading edge and a second interior conduit forward of the trailing edge. The conduits are centered on the chord and separated by a distance. A first cable having a first length is strung inside the first conduit and a second cable having a second length is strung inside the second conduit, and an adjustment mechanism is used to vary the length of the first cable relative to the length of the second cable and vice versa.

Abstract: A segmented-foil divertor for marine towed application, such as marine seismic exploration, having a plurality of longitudinally stackable foil segments with an internal conduit extending along the span of each segment to receive a cable passing therethrough.

Abstract: A foil having a leading edge, trailing edge, chord and span is attached between a first head float position and bottom submerged position below the head float on the array. The foil being flexible along its span and has a first interior conduit rearward of the leading edge and a second interior conduit forward of the trailing edge. The conduits are centered on the chord and separated by a distance. A first cable having a first length is strung inside the first conduit and a second cable having a second length is strung inside the second conduit, and an adjustment mechanism is used to vary the length of the first cable relative to the length of the second cable and vice versa.

Abstract: The present invention provides methods, systems and apparatus for steering one or more cables towed through water by a vessel. In general, a diverter attached to the one or more cables may comprise a float, a vane extending from a bottom surface of the float, and one or more vortex generators disposed on a suction side surface of the vane. The one or more vortex generators may prevent stall of the diverter at high attack angles.