Abstract: One or more docking cages releasably attached to a tow line extending from the stern of a retrieval ship, emit tracking beacon beams picked up by sensors in unmanned underwater sea craft vehicles being approached, for steered propulsion thereof into rammed hook attachment to the cages. A sea craft vehicle thereby releasably attached to a cage, is towed onboard the retrieval ship by storage reel-in of the tow line, which is then disconnected from the cage and the retrieved vehicle for subsequent use in retrieval of other unmanned sea craft vehicles.

Abstract: An unmanned sea vehicle is provided with a canister storing therein a net assembly in a deflated condition attached to the sea vehicle through the canister by a lanyard in a folded condition. The net assembly is connected to an inflation gas generator through which it is inflated to initiate retrieval of the unmanned sea vehicle. Inflation of the net assembly effects ejection thereof from the canister afloat onto a body of seawater, while connected to the canister on the sea vehicle by the unfolded lanyard. The floating net assembly is thereby positioned for engagement by a grappling hook lowered from a helicopter for example so as to lift it with the sea vehicle suspended therefrom by the lanyard from the sea water surface and transferred to the deck of a retrieval sea vessel.

Abstract: A parallelgram arrangement of linkages interconnect a stern ramp frame with a plurality of parallel rails vertically adjusted to positions above the ramp frame by actuators for reception and maintenance of a watercraft thereon with minimized vibration, further reduced by shock-absorbing springs positioned in engagement with the rails and the rail actuators. Rail positioning adjustment by the actuators is effected under computer control to match different hull shapes of the watercraft that are curved or v-shaped and therefore non-flat.

Abstract: A grapple anchor device suspended underwater from an unmanned watercraft has prongs pivotally mounted on its tubular housing for hooked engagement with a tow line extended from a retrieval ship so as to tow the watercraft underwater toward the ship. A tow rod within the grapple anchor housing, connected by an anchor line to the watercraft being towed, undergoes dampened axial displacement to condition the grapple anchor device for automatic release of the prongs from the tow line in response to a reduction in the towing force exerted through the tow line after the watercraft is towed into position adjacent the retrieval ship and undergoes crane lift up onto the retrieval ship by its shipboard crane so that the tow line may be withdrawn while the watercraft is transferred onto the ship.

Abstract: An underwater retrieval body connected at its forward bow end by a towing line to a retrieval ship, has attachment facilities at its opposite aft end for attachment thereof during underwater propulsion with an unmanned watercraft by engaging its projecting hook or reception of a projecting probe. During propulsion of the underwater retrieval body toward the unmanned watercraft, it is maneuvered into alignment therewith through steering rudder fins under control of a homing control system on the underwater retrieval body, in response to reception of tracking signals emitted from the unmanned watercraft.

Abstract: The forks of a conveyor tray are hingedly mounted between two end forks rdly interconnected by a cross-bar and through which electrically powered drive chains impart movement to the tray along a vertical conveyor path. The hingedly mounted tray forks are releasably held in normal load-supporting positions on the cross-bar in alignment with the two end forks, so that they may be pivotally displaced upwardly from such positions by travel resistance forces in excess of a safety level.

Abstract: A floating object is attached to a shipboard hoisting crane through its attachment device under high seawave conditions, by maintaining alignment of the crane attachment device under maneuvering thrust control with a location on the floating object during lowering of the attachment device onto the floating object. Such maneuvering thrust control is established by thrust jets emitted from the attachment device under control of optical scanning detection cells mounted on the attachment device for reception of a reception location indicating beam emitted from the floating object.