An example line restraint system comprises a housing, a processor, a motor, a release cam, and a timer. The release cam comprises a stem portion and an arm portion. The stem portion is proximate to the housing and the arm portion may be opposite the stem portion. The stem portion may be rotatably coupled to the motor. The motor may be 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 at least partially defines a cavity capable of retaining a release line. When in the open state, the release cam opens the cavity to enable release of the release line. The timer may receive instructions from the processor to set a particular time and to trigger the motor to turn the release cam from the closed state to the open state.

A crustacean trap adapted to permit blocking entry to a crustacean of a protected species, including a cage, enclosing a volume and a crustacean entrance that can be closed to prevent entry, responsive to a first signal and opened to permit crustacean entry, responsive to a second signal received at the trap. Also, an image forming assembly includes a digital camera and a flash mechanism, the assembly being directed at an area immediately outside of the entrance and being tuned to return a maximum signal from crustaceans of the protected crustacean species so that a protected species crustacean appears as brightly lit in images formed, and being communicatively connected to a remote station that is equipped to receive-images from the assembly. Finally, there is a connector for connecting the cage to a signal source for receiving the first and second signals and for sending the images formed.

A crustacean trap adapted to permit blocking entry to a crustacean of a protected species, including a cage, enclosing a volume and a crustacean entrance that can be closed to prevent entry, responsive to a first signal and opened to permit crustacean entry, responsive to a second signal received at the trap. Also, an image forming assembly includes a digital camera and a flash mechanism, the assembly being directed at an area immediately outside of the entrance and being tuned to return a maximum signal from crustaceans of the protected crustacean species so that a protected species crustacean appears as brightly lit in images formed, and being communicatively connected to a remote station that is equipped to receive-images from the assembly. Finally, there is a connector for connecting the cage to a signal source for receiving the first and second signals and for sending the images formed.

A water pressure-activated end line severing device is configured to be attached to a lobster, crab or snow crab trawl end line and to automatically sever the end line if a large marine animal has snagged, bitten, seized, caught, become entangled with, or otherwise somehow attached itself to that end line. When any large marine animal, such as a whale, snags or becomes entangled in the end line, the normal, instinctive response of the large marine animal is to dive rapidly to a greater depth, which pulls the end line and the device attached to the end line to a greater depth in the water column. As the device descends to a greater depth in the water column, the water pressure exerted against the device rapidly increases. When the water pressure reaches and exceeds a predefined water pressure threshold, a trigger assembly on the device activates a spring-loaded cutter assembly, which forces movement of a cutting blade to sever the part of the end line that passes through an aperture in the device, thereby freeing the large marine animal from the end line and the weight of the lobster or crab trawl.

A water pressure-activated end line severing device is configured to be attached to a lobster, crab or snow crab trawl end line and to automatically sever the end line if a large marine animal has snagged, bitten, seized, caught, become entangled with, or otherwise somehow attached itself to that end line. When any large marine animal, such as a whale, snags or becomes entangled in the end line, the normal, instinctive response of the large marine animal is to dive rapidly to a greater depth, which pulls the end line and the device attached to the end line to a greater depth in the water column. As the device descends to a greater depth in the water column, the water pressure exerted against the device rapidly increases. When the water pressure reaches and exceeds a predefined water pressure threshold, a trigger assembly on the device activates a spring-loaded cutter assembly, which forces movement of a cutting blade to sever the part of the end line that passes through an aperture in the device, thereby freeing the large marine animal from the end line and the weight of the lobster or crab trawl.

An example line restraint system comprises a housing, a processor, a motor, a release cam, and a timer. The release cam comprises a stem portion and an arm portion. The stem portion is proximate to the housing and the arm portion may be opposite the stem portion. The stem portion may be rotatably coupled to the motor. The motor may be 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 at least partially defines a cavity capable of retaining a release line. When in the open state, the release cam opens the cavity to enable release of the release line. The timer may receive instructions from the processor to set a particular time and to trigger the motor to turn the release cam from the closed state to the open state.

An example line restraint system comprises a housing, a processor, a motor, a release cam, and a timer. The release cam comprises a stem portion and an arm portion. The stem portion is proximate to the housing and the arm portion may be opposite the stem portion. The stem portion may be rotatably coupled to the motor. The motor may be 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 at least partially defines a cavity capable of retaining a release line. When in the open state, the release cam opens the cavity to enable release of the release line. The timer may receive instructions from the processor to set a particular time and to trigger the motor to turn the release cam from the closed state to the open state.

In accordance with at least one aspect of this disclosure, a crustacean trap can include a cage configured to trap one or more crustaceans, and a propulsion system connected to the cage and configured to provide propulsion to the cage. In certain embodiments, the trap can include a controller configured to control the propulsion system to autonomously pilot the trap.

In accordance with at least one aspect of this disclosure, a crustacean trap can include a cage configured to trap one or more crustaceans, and a propulsion system connected to the cage and configured to provide propulsion to the cage. In certain embodiments, the trap can include a controller configured to control the propulsion system to autonomously pilot the trap.

A retrieval system and methods of preparing and using same to retrieve underwater objects from a selected depth, including a flotation device having at least a selected amount of buoyancy, a release mechanism that is capable of releasably engaging an anchor, and a controller to actuate the release mechanism when a selected condition is achieved. The system further includes a spool assembly having a frame for carrying (i) the floatation device, (ii) the release mechanism, (iii) the controller and (iv) in combination with the flotation device, a quantity of pre-wound line having a length greater than the selected depth.