A bridle block is for a deflector, and has a stem and a rocker arm attached to each other on a pivot axis. The stem has an attachment for a vessel towline, a forward portion of the rocker arm has an attachment for fore bridle lines of the deflector, and an aft portion of the rocker arm has an attachment for aft bridle lines of the deflector. A hydraulic cylinder has a valve, and is attached to the stem and the rocker arm to hold the stem and the rocker arm in a relative position. The valve is operated by a signal from a control unit. The valve takes an open position when a signal is missing, so there is an open fluid connection between a piston side of a piston and a reservoir or an open fluid connection between the piston-rod side of the piston and the reservoir.

The invention has a curved board. The curved board is formed into a shape that curves in a curving direction corresponding to an expanding direction of a net opening in a towing state, from a front-side end section that is a front side in a towing direction in the towing state towards a rear-side end section that is a rear side in the towing direction in the towing state. At least one of a projecting structure having a projecting surface, a top board, and a bottom board is formed in the curved board.

The invention has a curved board. The curved board is formed into a shape that curves in a curving direction corresponding to an expanding direction of a net opening in a towing state, from a front-side end section that is a front side in a towing direction in the towing state towards a rear-side end section that is a rear side in the towing direction in the towing state. At least one of a projecting structure having a projecting surface, a top board, and a bottom board is formed in the curved board.

The present invention relates to trawl doors used in trawl fishing, including shallow water trawl fishing applications, deep water trawl fishing applications, bottom trawl fishing applications as well as at pelagic trawl fishing applications. The invention also relates to seismic surveillance line spreading and spreading of other items towed in water. The present application provides a novel trawl door design with improved stability and efficiency. The inventors are able to demonstrate smaller angles of attack using the trawl door of the present invention, which is as little as 7.5 degrees.

The present invention relates to trawl doors used in trawl fishing, including shallow water trawl fishing applications, deep water trawl fishing applications, bottom trawl fishing applications as well as at pelagic trawl fishing applications. The invention also relates to seismic surveillance line spreading and spreading of other items towed in water. The present application provides a novel trawl door design with improved stability and efficiency. The inventors are able to demonstrate smaller angles of attack using the trawl door of the present invention, which is as little as 7.5 degrees.

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.

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.

A segment for use in a trawl system having a cable and a longitudinal axis. The segment has a segment body and at least one passage extending from an inner side to an outer side of the body for receiving the cable of the trawl system. The segment body is hydrodynamically shaped such that the segment is urged away from the longitudinal axis when the segment is pulled through water by the cable. A trawl net system is also disclosed.

A segment for use in a trawl system having a cable and a longitudinal axis. The segment has a segment body and at least one passage extending from an inner side to an outer side of the body for receiving the cable of the trawl system. The segment body is hydrodynamically shaped such that the segment is urged away from the longitudinal axis when the segment is pulled through water by the cable. A trawl net system is also disclosed.

A method and system for efficient and eco-friendly shrimp skimmer trawling by a trawling vessel with a trawl net, skimmer booms, net arms, and buoyantly adjustable rollers to maintain trawl net height and net opening without damage to the ocean floor allowing for systematic and frequent retrieval of catch while continuing trawling operations in intervals short enough to prevent death of by-catch and endangered species and where the system is fully storable on trailerable trawling vessels for maintenance of allowable highway heights. The system and method has the upper edge of the trawl net held above the ocean surface while the trawling vessel moves forward.