Patent Application
20180201349
The present invention generally relates to a passive, non-lethal marine vessel defense apparatus and system that can immobilize attacking watercraft.
Maritime piracy (as well as acts of terrorism) targeting both commercial and non-commercial vessels has become increasingly prevalent in recent years. According to available data, there were approximately 400 reported pirate attacks globally in 2009, out of which about 150 vessels were boarded, over 50 vessels were hijacked, and over 100 vessels were fired upon; also, over 1,000 crew members were taken hostage with about 70 being injured and around 10 confirmed deaths. The comparative numbers for 2008 show about 300 reported incidents and about 40 vessels hijacked. The Gulf of Aden, a hot bed of piracy, was the site of about 120 attacks. Somali pirates have been identified as being responsible for over 200 acts of piracy in 2009, and their reach now extends more than 1,000 miles from the coast of Somalia. The percentage of successful hijackings in the Indian Ocean was about 25% of the vessels attacked through the last quarter of 2009. The over 50 successful hijackings in 2009 resulted in approximately $177 million in total ransoms paid to Somali pirates. In 2010, although there were fewer hijackings (about 44), total ransoms paid were higher, at about $238 million. The attacks continue to increase as have the average quantum of the ransoms paid.
Pirates have proven that the use of high speed conventionally powered small watercraft is highly effective and very difficult to deter. Prior experience in the Gulf of Aden has shown that successful attacks are typically conducted during twilight hours, from astern of and on the port quarter of the targeted vessel. The increased military presence in the Gulf of Aden has effectively forced Somali pirates to extend and venture farther out into the Indian Ocean where potential targets are afforded less protection. They have managed to do this by utilizing hijacked vessels as mother ships. This has enabled pirates to attack vessels up to 1000 miles off the coast of Somalia. Pirates usually favor vessels that are alone, slow moving and loaded, hence with low freeboards.
It is the general policy of insurance companies to pay the very high ransoms demanded for hijacked international flag vessels, cargoes and crews. Indeed, the surge in activity off the east coast of Somalia has, as noted above, led to ransom payments in excess of $200M for this region alone. The total cost of piracy has recently been reported to be about $12 to 15 billion annually. Insurance companies have increased tenfold surcharges for sending a cargo shipment through the Gulf of Aden (according to Lloyds List, approximately 20,000 vessels transited the Gulf of Aden in 2009 alone). Single trip policies through the Gulf of Aden with a $3 million ransom clause, can cost around $30,000, with additional premiums for crew liability. The hike in insurance rates has caused many ship operators to plot routes south of Africa and the Cape of Good Hope. However, this is not always cost effective when carrying time sensitive cargo. Lloyd's estimates the average increase in cost to sail this southerly route to be about $80,000 per trip.
The current deterrents being utilized generally favor the use of armed guards/escorts or other lethal force. However, international authorities have been reluctant to recommend such danger prone and potentially lethal methods. Also, the cost of hiring a security escort to pass through the Gulf of Aden/Suez Canal can be as much as $100,000, depending on the ship's size and the value of its cargo. The costs associated with deployment of armed guards are increasing relative to the ever expanding need for protection. The further drawback of this type of protection is that the vessel is only protected while the guards are embarked. Armed resistance also triggers many other concerns.
Therefore, there is an urgent need for a primary, stand-alone, passive, non-lethal and cost-effective marine vessel defense apparatus and system that can be deployed by the vessel's own crew to immobilize an attacking watercraft (whether detected or undetected) before it can reach the vessel.
More recently, military vessels, cruise liners, and luxury yachts have also been the subject of terrorist suicide speedboat attacks. Such vessels have a generally static displacement and waterline (e.g., they maintain generally the same drift displacement whether under load or unloaded), which can benefit from a non-lethal, passive protection system that can be installed and stowed sub-surface so as to not affect the aesthetic appearance of the vessel.
Generally speaking, the present invention is directed to embodiments of a new, non-lethal watercraft immobilizing apparatus and system that can be deployed from any marine vessel to defend against attacking engine powered watercraft. Improving over conventional net-deploying systems, embodiments of the present invention include a towed array of wires, SPECTRA lines, polymer or nylon lines (“tendril lines” or “lines”) at or below the water surface, which may be weighted for neutral buoyancy. The towed array of tendril lines can foul and immobilize propellers and engine cooling water intakes of attacking watercraft (whether or not detected). An arrangement of secondary and possibly tertiary tendril lines can also be deployed from the primary lines.
The towed lines can be deployed from removable/replaceable cartridges (that can be disposed of after use or refurbished). The cartridges can be mounted on supports or outriggers positioned strategically about the assailable faces of the vessel.
Banks of suspended, weighted, submersible dual rollers can be included to direct the tendril lines fed from the cartridges, which can be deployed and recovered manually or automatically by means of motors, for example. Each bank of rollers can feature secondary winches or davits at the extremities that can also be operated by motor. The winches or davits can hold the wire/line that deploys the weighted submersible dual rollers for each bank. The weighted dual rollers can be configured to place the towed array at or below the water surface adjacent to the cartridges.
A main bank of rollers can be mounted off the vessel's transom (e.g., suspended not from outriggers but from the vessel's existing aft structures, such as, for example, the aft bulwark). Two transom outriggers (e.g., one at each extremity of the vessel), can each be configured to deploy its own bank of rollers. The weighted submersible dual rollers in the way of these two aft outriggers can be configured to be connectable to the extremities of the rollers of the main transom bank, effectively forming one unit. Deep fins can be situated at the outer extremities of these rollers to prevent the lines of the towed side arrays from fouling the vessel's own propeller(s).
Additional outriggers can each be configured to deploy its own bank of rollers at the vessel's forward shoulders (e.g., on port and starboard sides). These banks can be similarly fitted with powered submersible dual rollers to effectively deploy side arrays to shield the vessel's sides. Each cartridge can administer multiple main lines and/or an array of tendril lines through the adjacent submersible roller(s). The ends of each of the main lines for each cartridge can be held in a submerged pattern by weighted spreader bars, which can be finned for improved stability.
Alternatively, or in addition, two or more davits/outriggers (e.g., one at each extremity of the vessel at a forward position such as the focsle of the vessel, and/or one at each extremity of the vessel at an aft position such as the transom of the vessel) can be configured to deploy one or more drogues/foils/rudders (e.g., deep-finned, floated, and buoyant), which can be similar to paravanes, (hereinafter, “paravanes”). The paravanes can be interconnected by a transverse submersible wire/chain that can support rollers. The paravanes can be towed from wires streamed from forward positions to prevent the paravanes and transverse submersible wire or chain from trailing aft of the transom. For example, in some embodiments, each paravane can be towed by one or more wire, chain or SPECTRA booms (hereinafter, “floated booms”), which can be held in position from the vessel's stem by a traveling block, folding bowsprit, or hard connection to the hull of the vessel. Thus, each paravane and respective floated boom(s) can mutually hold each other in position.
The side array of tendril lines can then be streamed from one or more of the floated booms. Main tendril lines are preferably fitted with secondary paravanes so as to hold the lines generally parallel to the vessel's hull. In some embodiments, when utilizing the optional hard connection to the hull of the vessel (e.g., port and/or starboard bow), the floated boom can be stored in a bight from the head of the foremast, which can provide protection that is simple and cost effective. Tendril lines of the main stern bank can then be fed through links of the interconnecting submersible wire/chain (or rollers supported by the interconnected wire/chain), which can hold the tendril lines in/on the water below (e.g., immediately below) the transom.
Alternatively, or in addition, banks of storage rollers can be provided at the vessel's focsle (e.g., on port and starboard sides). These banks can be similarly powered to feed the tendril lines through floated booms (e.g., on port and starboard sides) to effectively deploy the side arrays and shield the vessel's sides. Each cartridge can be situated on one or more of the self-tensioning winches and can administer multiple main lines and/or an array of tendril lines through the adjacent floated booms. The ends of each of the main lines for each cartridge can be held in a submerged pattern by finned floats and/or spreader bars, which can also be finned for improved stability.
In some embodiments, the paravanes can be configured to prevent the possibility of the lines of the towed side arrays from fouling the vessel's own propeller(s). The paravanes can be deep-finned, situated at or just below the sea or water surface (e.g., approximately 20 to 30 degrees abaft of the stem on both the port and starboard sides of the vessel). The floated booms can be fitted with eyes or rollers (which can include storage rollers) positioned at suitable intervals through which the tendril lines can be fed. The floated booms can feed the lines into the water forward of the storage positions of the lines.
The floated booms, paravanes and tendril lines can be deployed and/or recovered by separate winches or davits. It should be appreciated that the floated boom and paravane assembly deployed from the stem of the vessel can dramatically increase the area of protection along the vessel's sides and can also provide protection of the bow of the vessel.
Vessels with static displacements, such as warships, cruise liners, and luxury yachts, may be fitted with paravanes having collapsible or foldable wings. In an exemplary embodiment, main paravane(s) can be launched from a tube or chamber at or above the water surface (e.g., such as from a mortar) or, alternatively, below the water surface (e.g., such as from a torpedo tube). The chamber or tube can be fitted with one or more watertight doors, and can be sized to store the floated boom and entanglement lines, in addition to the paravanes. The floated boom can be hard terminated to the vessel's hull, and configured to allow remote and/or automatic release/jettison. The main paravanes are preferably fitted with independent propulsion systems, such as, for example, rocketry or conventional electric motors/propellers. The paravanes are also preferably configured to emit a smoke screen. In certain smaller vessels, the paravanes can alternatively be stowed at or adjacent to the vessel's transom, and the floating boom and entanglement lines can be stowed on or in a mount situated, for example, on and along at least a portion of the full length of the starboard and/or port sides of the hull, below and (e.g., immediately) adjacent to the waterline.
The watercraft immobilizing apparatus and system according to embodiments of the present invention can be deployed remotely (e.g., from the vessel's bridge), and as quickly as the vessel's own speed through the water. The vessel does not have to reduce speed for deployment or recovery.
It is therefore an object of the present invention to provide a passive, non-lethal, easy-to-use, cost-effective defensive shield around a marine vessel to immobilize and thus repel attacking watercraft (whether or not such watercraft have been detected).
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The present invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.
For a fuller understanding of the present invention, reference is had to the following description taken in connection with the accompanying drawings in which:
In accordance with embodiments of the present invention, a passive, non-lethal marine vessel piracy defense apparatus and system are provided that can be deployed about the assailable faces of the vessel to repel attacking watercraft by fouling and thus immobilizing their propellers and engine intakes. Generally speaking, this is accomplished by a towed (at or below the water surface) array of entanglement tendril lines.
Marine engines are designed to propel a craft by moving water in various ways, for example through open or enclosed propellers, through jet engines and through cooling systems. It will be appreciated that the towed array according to embodiments of the present invention moves with this water into the attacking vessel's propellers, cooling intakes or jet intakes, hence fouling and stopping the engine(s).
It will also be appreciated that the towed array according to embodiments of the present invention provides a defense against piracy that can be characterized as “passive” because the array remains deployed throughout a voyage without unduly interfering with vessel operations. Moreover, when in a deployed state, attacking watercraft need not be detected in order to repel an attack.
The towed tendril lines can be engineered to break free when the mass of an entangled attacking watercraft is exerted on the towed array, hence releasing the watercraft adrift. Attacking watercraft can entangle very quickly on relatively few lines.
The tendril lines can be formed from polymer, nylon or SPECTRA lines, or from wires, and can be weighted for neutral buoyancy (e.g., weighted or coated with emulsion). The tendril lines can also advantageously be formed from a biodegradable material. For example, BIOLINE with an active shelf life of six to twelve months, which is purported to be a biodegradable product engineered to protect the environment, can be used. According to its manufacturer, BIOLINE is made from a biodegradable polymer that will completely biodegrade within five years (in its twelve month usable life format); and it can be engineered to biodegrade more rapidly. Regular monofilament or fluorocarbon line takes over six hundred years to biodegrade. Preferably, the lines can have negative buoyancy when cast adrift so that they can sink to the seabed.
An arrangement of secondary and possibly tertiary lines deployed from the primary tendril lines at or just below the water surface can also be provided. These tendril lines can have varying lengths, and can be staggered at intervals of, for example, five feet, along the primary lines.
Furthermore, as described in greater detail hereinafter, the towed array of tendril lines can be deployed via floated wire/chain/SPECTRA booms, which can be positioned by a surface tube (e.g., mortar), sub-surface tube or chamber, traveling block, folding bowsprit, floated paravanes (e.g., with or without collapsible or foldable wings), hard connection to the hull of the vessel, outriggers, rollers, and/or spreaders.
The tendril lines can be administered from reusable/removable/replaceable (and even disposable or refurbishable) cartridges. Each cartridge can administer multiple main lines (which can, for example, be fitted with secondary paravanes) and, possibly, an array of sub-tendril lines, through links or eyes of the floated booms, and/or by way of rollers. The ends of each of the main lines for each cartridge can be held in a submerged pattern by finned floats and/or spreader bars (and/or intermediate spreaders), which can be suitably finned and/or weighted to push the tendril lines away from the side of the vessel. This can also improve stability.
Damaged sections of the towed array can be replaced by removing and inserting a new or reconditioned cartridge. Cartridges can include the neutrally weighted multiple main lines, secondary and tertiary lines along with secondary paravanes, otters, planer boards, and/or spreaders. Alternatively, the entire watercraft immobilizing apparatus and system, including the floated booms and paravanes, can be released and jettisoned (e.g., when deemed safe to do so).
Where fitted, banks of the rollers can be configured to feature multiple ones of the removable cartridges and can be easily and rapidly deployed/recovered manually (e.g., gravity deployment from a spring tension device) or automatically (including by remote control, by means of electric/hydraulic motors, for example). Each bank can feature secondary winches at the extremities, which can also be operated manually or remotely by electric/hydraulic motor. These winches can store the line/wire that deploys (suspends) weighted submersible dual rollers for each bank.
The weighted dual rollers can be used to place and hold the towed array below the water surface beneath the cartridges. These dual rollers can be further secured below the deployment banks to prevent the rollers from riding aft and above the water surface by preventer wires led from the extremities of the rollers to a strong point on deck forward of the roller installation.
A main bank of rollers can feature multiple removable cartridges and can be mounted off the vessel's transom. Additionally, two transom outriggers, one at each extremity, can deploy further banks of rollers also featuring multiple removable cartridges. The weighted submersible dual rollers in the way of these aft outriggers can be connected to the extremities of the weighted submersible dual rollers of the main transom bank, effectively forming one unit. Deep fins can be provided at the outer extremities of these rollers to prevent the possibility of the lines of the towed side arrays fouling the vessel's own propeller(s). Additional outriggers, which can be deployed at other locations to shield the vessel, can deploy rollers that also feature multiple cartridges. These banks can be similarly fitted with submersible dual rollers. The towed side arrays can also be fitted with independent spreaders appropriately finned.
Each storage bank of rollers can deploy a suitable amount (length) of towed tendril lines supporting multiple sub-tendril lines in a varying pattern to give practical full, all-round protection and to maximize the arresting effect of an attacking watercraft's propeller or intake system.
Referring now to the drawing figures,
It should be understood that the only locations on the vessel that may not need to be protected by towed arrays are the bow areas, where the bow wave creates a highly dangerous position for smaller boats to attack. However, some embodiments described hereinafter in greater detail provide protection for the bow areas as well.
Where fitted, each bank of rollers (e.g.,
Where fitted, the submersible rollers need not be heavy, bulky pieces of equipment, and can be deployed from separate electric/hydraulic motors and winches. The submersible rollers can be lowered directly from the storage banks.
The main transom bank of rollers can be fitted by steel brackets to the vessel's existing structures, such as the aft bulwark (
The main storage bank (
For example, two stern quarter outriggers/davits (
Where fitted and deployed, the stern quarter outriggers can be in a generally perpendicular position, but the outriggers can also be rotated parallel to the vessel's main axis and removed when not in use and locked in stowed or deployed positions. The body of the outrigger can similarly support multiple flanges that incorporate intermediate (preferably, stainless steel) shafts and bearings. The intermediate shaft ends can be similarly notched to receive the removable cartridge shafts that are similarly locked in place. The complete quarter outrigger shaft assemblies can then be driven by inboard mounted electric/hydraulic motors, which can be remotely controlled. These quarter outrigger shaft assemblies can also be fitted with locking devices to prevent forced rotation when the tendril array is deployed.
Secondary winches, similarly powered by electric/hydraulic motors, can be situated at the extremities of the quarter outrigger storage bank rollers. These winches can store the support wires for the quarter outrigger bank dual submersible weighted rollers (
Alternatively, or in addition, secondary winches (
In some embodiments, forward shoulder outriggers (FIGS. a, 5, and 6) can also be configured to deploy side towed arrays (e.g., not less than twenty feet in width/span) off the port and starboard sides of the vessel. These side towed arrays can extend aft to a desired length and can overlap the stern mounted towed array, outboard of the deep fin positioned at the extremities of the stern quarter dual submersible roller.
These forward outriggers, which can be situated at the port and starboard shoulders of the protected vessel, can be configured to be the same as or similar to the stern quarter outriggers. In some embodiments, the forward outriggers can be larger than the stern quarter outriggers. These forward outriggers can also be rotated parallel to the vessel's main axis when not in use and locked in stowed or deployed positions. The body of each outrigger can similarly support multiple flanges that incorporate intermediate (preferably, stainless steel) shafts and bearings (
The towed side arrays themselves can cause a vector of force away from the vessel and can help hold the forward submersible rollers off the vessel's side. The rollers can also be fendered on the inboard side. Also, the rollers can be segmented (e.g., cartridge width—every five feet) and fitted with cutting edges to sever lines entangled between adjacent cartridges to allow more efficient re-spooling. The cartridges themselves can have intermediate flanges to segment tendril line.
Similar to the towed stern arrays, the trailing spreaders of the towed side arrays can inter-connect (attach between each cartridge) and form a substantially rigid boom. The towed side array spreaders can also be finned to encourage movement out and away from the side of the protected vessel. The towed side arrays can be run out to the approximate turning circle of the vessel.
Referring now to
Floated boom 1110 can be situated at port and/or starboard sides of the vessel and streamed from a traveling block 1000, a folding bowsprit 1410, and/or a hard connection 1560 to the hull of the vessel. Floated boom 1110 can provide a barrier, hence affording enhanced protection at the bow. It should be understood that a primary purpose of the floated booms (and the submersible rollers of the embodiments described above) is to get the tendril lines into the water directly below or forward of the deployment banks (e.g.,
Paravanes 1120 can be stored and deployed by davit/outrigger 1140 fitted on port and/or starboard sides of the vessel (e.g., at the extremities and to the vessel's focsle and/or poop deck). Davit/outrigger 1140 can also be operated manually or remotely by electric/hydraulic motor. In some embodiments, each davit/outrigger 1140 can be powered by electric/hydraulic motors to deploy paravane 1120 via an interconnecting transverse submersible wire/chain 1420 (that can support rollers). Each paravane 1120 can also be towed from floated boom 1110 and/or separate recovery wires 1180 streamed from forward positions to prevent the paravane and transverse submersible wire/chain 1420 from trailing aft of the transom. Paravane 1120 can prevent the possibility of the lines of the towed side arrays 1190 from fouling the vessel's own propeller(s). In some embodiments, bridle 1130 can be configured to couple paravane 1120 and recovery wire 1180 and/or transverse submersible wire/chain 1420.
In some embodiments, tendril lines of the main stern bank can be fed through links of interconnecting submersible wire/chain 1420 (or rollers supported by interconnected wire/chain 1420), which can hold the tendril lines in/on the water below (e.g., immediately below) the transom. Interconnecting submersible transverse wire/chain 1420 can be held tight, due to the tensile force that can be created by the angle of the fins in way of the paravanes.
In some embodiments (see e.g.,
In some embodiments (see e.g.,
In some embodiments (see e.g.,
Irrespective of whether traveling block 1000, bowsprit 1410, or hard connection 1560 is employed, rollers can be fitted to feed the tendril lines (e.g., of transom and/or focsle storage banks on port and starboard sides) on or into the water.
Referring to
By definition, the force generated on an airfoil has two components: the drag and the lift. Lift is always perpendicular to the flow. The drag component is also known as “induced drag” and can be calculated using the following formula:
L=C
D0.5ρSV2
The lift created, which should balance the drag generated by the entanglement tendrils and the boom, can be described by the following formula:
L=C
L0.5ρSV2
where:
The dimension of the blade can be determined by the lift requested. Determination of the lift coefficient can depend primarily on the angle of attack and also on the cross-sectional profile of the blade. The cross-sectional profile giving a suitable (which can be the best) lift is that of the NACA 6712 as illustrated in
The forces to be taken into account are illustrated in
In order to balance the tendril drag, the moment (about the bow) of the lift should equal the moment (about the bow) of the total drag, generated by the tendrils and boom; the forces and relative arms with respect to the bow (Point A) are shown in
The tendril drag is being considered as concentrated at half length of the boom. In calculating the moments, the arms of drag and lift are:
Drag: half of the boom length+clearance from the side of the vessel+half of the width of the vessel; and
Lift: lift between the paravane and the bow of the vessel (point A)=length of the forecastle.
The relevant data for the chosen profile can be found in the National Advisory Committee for Aeronautics Report No. 460, titled “The Characteristics of 78 related airfoils sections from tests in the variable-density wind tunnel” published in 1935.
For the profile NACA 6712, the relation between the angle of attack and the lift/drag coefficient is as shown in
With α, CL and CD set, the remaining values can be calculated as follows:
The dimension of the paravane blade can therefore be as set forth in
Current naval architecture load requirements mean that lighter systems can be used. Accordingly, a light-weight tubular (even portable) construction can advantageously be used for the outriggers with the motors mounted inboard (to the main pivot point/mounting adjacent to the support) to further reduce overall weight. This can save considerable expense associated with stiffening and shipping. The weight of this equipment will not affect the vessel's cargo carrying capacity at all. Also, the light-weight tubular alloy construction can permit longer outriggers (the outriggers can be up to 20 m in length, for example) with minimum support strengthening. The tubular outrigger construction can also be easily fitted, and require only minimal under-deck reinforcement.
Required deck space is minimized by the inventive embodiments. The outriggers can stow in line and over the top of the vessel's existing railings.
Also, the drag effect is minimal (about 40 Kg per cartridge assuming deployment length of the full 3,000 feet). The maximum drag on the forward outriggers is expected to be about 160 Kg (assuming pattern density on 2.5 cm (1 inch) centers). The maximum moment on the forward outriggers (attributable to drag) is expected to be about 600 Kg/m. The drag is a product of the coefficient of friction in water and vessel speed and is not adversely affected by weather/sea state.
Referring to
Referring to
Referring to
Referring to
As an alternative to the above-described constructions, only main tendril lines with no secondary, tertiary or other offshoots can be used, and the spacing between lines can be closed (e.g., on 1 inch centers) or otherwise adjusted. In such case, it can be desirable to use intermediate spreaders along the length of the towed arrays. This can enhance recoverability and re-usability and reduce cost. The main long lines can be fitted with swivels to allow rotation.
Additionally, in various embodiments, it is possible to exclude the aft outriggers and use only the transom mounted bank. It is also possible to use only shoulder outriggers, or to exclude the shoulder outriggers and use only the aft outriggers and/or transom bank.
Expediently, the deployment banks can hold reserve tendril lines. Also, a rendering device can be provided to manually or automatically play out additional tendril lines as needed in the event that lines are severed. The towed arrays can also be provided with an emergency release.
In certain embodiments, the outriggers can also be provided with fairing to prevent grappling hooks from hooking on thereto.
It should be appreciated that it is possible to provide embodiments of a watercraft immobilizing apparatus and system in accordance with the present invention that variously do not employ trailing end spreaders, or finned spreaders. It is even possible to substitute simple weight bars for submersible rollers, or to exclude the submersible rollers and simply deploy the tendril lines on the water surface.
It should be appreciated that the effectiveness of the watercraft immobilizing apparatus and system according to embodiments of the present invention can be increased by implementing vessel maneuvering practices when an attacking watercraft is detected. By way of example, when an attacking watercraft is in weapons range at the side or quarter of the protected vessel, the vessel can alter course towards the attacker and keep the helm hard over. This will effectively stall the towed side array on the attacker's side of the vessel. The vessel can complete a turn of approximately 270 degrees from its original heading to cross the trailing end of the stalled side array at approximately 90 degrees. If the attacking watercraft attempts to hold station on the vessel then it will be forced to cross the stalled side array.
Accordingly, the present invention provides embodiments of a marine vessel primary defense apparatus and system, novel characteristics of which, including its optional continuous deployment, in conjunction with recommended maneuvering procedures, provide a non-lethal, passive, cost-effective means to prohibit attacking watercraft from closely approaching a protected vessel whilst it is underway.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
This application is a continuation-in-part of U.S. patent application Ser. No. 15/371,943 filed on Dec. 7, 2016, which is a continuation of U.S. patent application Ser. No. 14/308,074 filed on Jun. 18, 2014, which is a continuation of U.S. patent application Ser. No. 13/305,309 filed on Nov. 28, 2011, which is a continuation-in-part of International Application No. PCT/US2010/001499, designating the United States, with an international filing date of May 20, 2010, and of U.S. patent application Ser. No. 12/473,659 filed on May 28, 2009, all the disclosures of which are incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14308074 | Jun 2014 | US |
| Child | 15371943 | US | |
| Parent | 13305309 | Nov 2011 | US |
| Child | 14308074 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15371943 | Dec 2016 | US |
| Child | 15834470 | US | |
| Parent | PCT/US2010/001499 | May 2010 | US |
| Child | 13305309 | US | |
| Parent | 12473659 | May 2009 | US |
| Child | PCT/US2010/001499 | US |
