System for Immobilizing Small Watercraft

Abstract

A system and method for a large ship to immobilize malicious small watercraft comprises of an unmanned underwater vehicle. The vehicle can be launched immediately upon detection of the threat. When the watercraft comes close, preparing to start boarding attack, the vehicle either uses it's onboard propulsion or is towed with a cable to sneak up on the watercraft and deliver an immobilizing effect, such as a hard crash or a stalling entanglement, on the propulsion mechanism of the watercraft.

What is claimed is: 
     
         1 . A system for immobilizing small watercraft, comprising:
 a towed vehicle, deployable from an operating ship upon detection of potential threat,   a tow cable attached to said vehicle,   a winch system such that said vehicle can be towed via said cable, to and fro, close to and alongside the starboard or port side of the operating ship,   a depth-control mechanism that enable said vehicle to stay at a predetermined depth under water surface,   a structure attached to said vehicle, capable of inflicting crippling effect to the propulsion mechanism of the watercraft, selected from the group consisting of
 a wide bumper area made of hard material for ramming the propeller of the watercraft, and 
 an entanglement device that can stall the propulsion mechanism of the watercraft. 
   
     
     
         2 . The system of  claim 1 , further comprising a monitoring camera subsystem employed by the operating ship to safely provide real time surveillance for the system operation. 
     
     
         3 . The system of  claim 1 , further comprising at least one light source mounted on the vehicle wherein said light source only emits light invisible to the human eye, whereby said vehicle can be more easily monitored by the operating ship while keeping stealth. 
     
     
         4 . The system of  claim 1  wherein said entanglement devise has more than one piece of entanglement material attached, whereby said vehicle can immobilize more than one watercraft during one deployment. 
     
     
         5 . The system of  claim 1  wherein said depth-control mechanism includes a hydrofoil and a ballast system. 
     
     
         6 . The system of  claim 1 , further comprising a communication means for said vehicle to receive control commands from the operating ship, such as RF antenna, acoustic transducer, electrical, and optical cable. 
     
     
         7 . The system of  claim 6 , further comprising a steering mechanism. 
     
     
         8 . The system of  claim 7 , further comprising a motion control subsystem to coordinate said towing and said steering whereby a simplified control interface can be provided. 
     
     
         9 . The system of  claim 6 , further comprising a depth adjustment mechanism. 
     
     
         10 . A system for immobilizing small watercraft, comprising:
 an unmanned underwater vehicle (UUV), deployable from an operating ship upon detection of potential threat, comprising:
 an onboard propulsion subsystem, 
 a depth-control mechanism that enable said UUV to stay at a predetermined depth under water surface, 
 a steering mechanism, 
 a communication means for said UUV to receive control commands from the operating ship, such as RF antenna, acoustic transducer, electrical, and optical cable, 
   a structure attached to said UUV, capable of inflicting crippling effect to the propulsion mechanism of the watercraft, selected from the group consisting of
 a wide bumper area made of hard material for ramming the propeller of the watercraft, and 
 an entanglement device that can stall the propulsion mechanism of the watercraft. 
   
     
     
         11 . The system of  claim 10 , further comprising a monitoring camera subsystem employed by the operating ship to safely provide real time surveillance for the system operation. 
     
     
         12 . The system of  claim 10 , further comprising at least one light source mounted on the vehicle wherein said light source only emits light invisible to the human eye, whereby said vehicle can be more easily monitored by the operating ship while keeping stealth. 
     
     
         13 . The system of  claim 10  wherein said entanglement devise has more than one piece of entanglement material attached, whereby said vehicle can immobilize more than one watercraft during one deployment. 
     
     
         14 . The system of  claim 10 , further comprising a tethering cable between said UUV and the operating ship, whereby said UUV can conserve propulsion power while waiting for the target watercraft to come into range. 
     
     
         15 . The system of  claim 10 , further comprising a homing guidance subsystem to home in on the target watercraft. 
     
     
         16 . The system of  claim 10  wherein said depth-control mechanism includes a hydrofoil and a ballast system. 
     
     
         17 . The system of  claim 10 , further comprising a depth adjustment mechanism. 
     
     
         18 . The system of  claim 10 , further comprising a motion control subsystem to coordinate said propulsion and said steering, whereby a simplified control interface can be provided. 
     
     
         19 . A method for immobilizing small watercraft, comprising:
 deploying an unmanned vehicle to be underwater nearby the operating ship;   waiting for the moment when the small watercraft is coming close to run alongside the operating ship;   maneuvering the vehicle toward the watercraft to deliver a crippling effect to the propulsion mechanism of the watercraft, said crippling effect is selected from the group consisting of
 damaging crash of the propulsion mechanism, and 
 Stalling entanglement of the propulsion mechanism. 
   
     
     
         20 . The method of  claim 19  wherein said maneuvering the vehicle toward the watercraft comprising moving the vehicle underneath the watercraft; and rising upward toward the watercraft.