Disclosed herein are systems and methods for ropeless fishing. The ropeless fishing system includes a surface subsystem installed on a vessel and at least one submerged subsystem submerged in a body of water. The surface subsystem includes acoustic transceiver and acoustic transducer units, which are configured to generate and omnidirectionally transmit an acoustic interrogation signal into the body of water surrounding the vessel and to directionally receive acoustic reply signals. The submerged subsystems include a compressed gas source and an enclosed flotation bag in fluid communication and an underwater acoustic actuator-transponder unit configured to receive the acoustic interrogation signal transmitted by the surface subsystem and to transmit an acoustic reply signal into the body of water. In addition, the submerged subsystem is further configured to control the flow of gas between the compressed gas source and the enclosed floatation bag to facilitate recovery of the submerged subsystem.

A magnetic release mechanism for use with underwater fishing equipment includes a base plate having a slot for receiving a buckle, and a recess for receiving a release plate. A permanent magnet positioned proximate the recess generates a first magnetic field for magnetically coupling the release plate to the base plate. An electromagnetic coil positioned proximate the permanent magnet is configured to selectively generate a second magnetic field when energized. A magnetic field sensor is positioned proximate the recess. A controller is operatively coupled to the magnetic field sensor. The controller may be configured to monitor the magnetic field sensor to detect the presence of a third magnetic field and, in response to detecting the presence of a third magnetic field, output a signal indicating that the release plate is magnetically secured within the recess.

An apparatus and technique for underwater storage and deployment of a fishing line and buoy includes a cylinder coupled to a fishing apparatus. A buoy is attached to a buoy line coupled to the fishing apparatus and the buoy line and buoy are stowed within the cylinder in a first position. A holding mechanism holds a top perimeter of the cylinder closed until intentionally released. Upon release of the holding mechanism, the buoy and buoy line escape the cylinder. The buoy then pulls the buoy line to the surface where the fishing apparatus can be recovered by the fisher.

An apparatus and technique for underwater storage and deployment of a fishing line and buoy includes a mesh cylinder coupled to a fishing apparatus. A buoy is attached to a buoy line coupled to the fishing apparatus and the buoy line and buoy are stowed within the mesh cylinder in a first position. A drawstring holds a top perimeter of the mesh cylinder closed until intentionally released. Upon release of the drawstring, the buoy and buoy line escape the mesh cylinder. The buoy then pulls the buoy line to the surface where the fishing apparatus can be recovered by the fisher.

A ropeless fishing gear retracting-and-releasing device has a casing, a buoyancy changing device, a power-supplying device, and a controller. The casing has a top cover mounted on a top opening, a bottom cover, and a through hole through the bottom cover. The buoyancy changing device has an upper seat and a lower seat in the casing, multiple fixing rods, a driver, and a piston. Two ends of each of the rods are respectively mounted on the upper seat and the lower seat. The driver is mounted in the casing. An end of the piston is connected to the driver. An accommodation space is formed between another end of the piston and the bottom cover and fluidly communicates with the through hole. The power-supplying device is mounted in the casing and electrically connected to the driver. The controller is mounted on the casing and electrically connected to the power-supplying device.

A ropeless fishing gear retracting-and-releasing device has a casing, a buoyancy changing device, a power-supplying device, and a controller. The casing has a top cover mounted on a top opening, a bottom cover, and a through hole through the bottom cover. The buoyancy changing device has an upper seat and a lower seat in the casing, multiple fixing rods, a driver, and a piston. Two ends of each of the rods are respectively mounted on the upper seat and the lower seat. The driver is mounted in the casing. An end of the piston is connected to the driver. An accommodation space is formed between another end of the piston and the bottom cover and fluidly communicates with the through hole. The power-supplying device is mounted in the casing and electrically connected to the driver. The controller is mounted on the casing and electrically connected to the power-supplying device.

An example line restraint system comprises a housing, processor, motor, release cam, and a receiver. The release cam comprises a stem portion opposite an arm portion. The arm portion may extend away from the stem portion of the release cam. The stem portion may be rotatably coupled to the motor with the motor being configured to turn the arm portion of the release cam between an open and closed state. When in the closed state, an overhang of the arm portion of the release cam at least partially defining a cavity capable of retaining a release line. When in the open state, the release cam opening the cavity to enable release of the release line. The receiver may be configured to receive an acoustic signal. The processor may be configured to trigger the release cam to turn based on the acoustic signal.

An example line restraint system comprises a housing, processor, motor, release cam, and a receiver. The release cam comprises a stem portion opposite an arm portion. The arm portion may extend away from the stem portion of the release cam. The stem portion may be rotatably coupled to the motor with the motor being configured to turn the arm portion of the release cam between an open and closed state. When in the closed state, an overhang of the arm portion of the release cam at least partially defining a cavity capable of retaining a release line. When in the open state, the release cam opening the cavity to enable release of the release line. The receiver may be configured to receive an acoustic signal. The processor may be configured to trigger the release cam to turn based on the acoustic signal.