Security barrier comprising: a substantially planar support element (2) having top and bottom edges, wherein respective top and bottom first attachment sites are formed at the top and bottom edges; and a bulbous barrier element (9), which is separate from the support element, having top and a bottom edges and respective top and bottom second attachment sites formed at the top and bottom edges, with a curved protruding section extending between the top and bottom edges, the protruding section extending away from the plane containing the top and bottom edges, wherein the support element and the barrier element are releasably connected to each other by way of the first and second top and bottom attachment sites, so that the support element and barrier element define an internal space therebetween which receives a horizontal rail, and wherein the security barrier may rest on the rail, a vertical plane being defined between the rail and the surface, so that the rail lies at or near the top edge of the support element and of the barrier element, the support element extends close to the vertical plane, and the protruding section protrudes outwardly from the vertical plane.

Security barrier comprising: a substantially planar support element (2) having top and bottom edges, wherein respective top and bottom first attachment sites are formed at the top and bottom edges; and a bulbous barrier element (9), which is separate from the support element, having top and a bottom edges and respective top and bottom second attachment sites formed at the top and bottom edges, with a curved protruding section extending between the top and bottom edges, the protruding section extending away from the plane containing the top and bottom edges, wherein the support element and the barrier element are releasably connected to each other by way of the first and second top and bottom attachment sites, so that the support element and barrier element define an internal space therebetween which receives a horizontal rail, and wherein the security barrier may rest on the rail, a vertical plane being defined between the rail and the surface, so that the rail lies at or near the top edge of the support element and of the barrier element, the support element extends close to the vertical plane, and the protruding section protrudes outwardly from the vertical plane.

A compressed air tank for sinking prevention comprises a compressed air tank having a valve; and an air pocket coupled to the compressed air tank and being filled with air discharged from the compressed air tank when the valve is opened, wherein buoyancy is provided to a cabin that is being flooded through the air pocket to prevent a ship from foundering.

A compressed air tank for sinking prevention comprises a compressed air tank having a valve; and an air pocket coupled to the compressed air tank and being filled with air discharged from the compressed air tank when the valve is opened, wherein buoyancy is provided to a cabin that is being flooded through the air pocket to prevent a ship from foundering.

A watercraft immobilizing apparatus and system for a marine vessel to passively defend against an attacking engine-powered watercraft includes a towed array of entanglement lines. The entanglement lines can be provided on and administered from reusable/removable/replaceable storage cartridges mountable on a hull mount or stowed in a watertight chamber in the vessel's hull, and/or deployed via floated booms and/or paravanes to foul and immobilize propellers and engine cooling water intakes of encroaching watercraft.

A watercraft immobilizing apparatus and system for a marine vessel to passively defend against an attacking engine-powered watercraft includes a towed array of entanglement lines. The entanglement lines can be provided on and administered from reusable/removable/replaceable storage cartridges mountable on a hull mount or stowed in a watertight chamber in the vessel's hull, and/or deployed via floated booms and/or paravanes to foul and immobilize propellers and engine cooling water intakes of encroaching watercraft.

A method and apparatus for stopping an impeller-driven watercraft is includes distributing a plurality of submunitions in advance of a path of the impeller-driven watercraft. Each of the submunitions includes a buoyant member, a first end cap, and a second end cap; the second end cap is heavier than the first end cap. A lanyard connects the first end cap to the second end cap, optionally passing through the buoyant member. At least one of the submunitions enters an intake vent of the impeller-driven watercraft and attaches to a blade of an impeller of the impeller-driven watercraft, causing cavitation and imbalance, thereby slowing the impeller-driven watercraft.

A method and apparatus for stopping an impeller-driven watercraft is includes distributing a plurality of submunitions in advance of a path of the impeller-driven watercraft. Each of the submunitions includes a buoyant member, a first end cap, and a second end cap; the second end cap is heavier than the first end cap. A lanyard connects the first end cap to the second end cap, optionally passing through the buoyant member. At least one of the submunitions enters an intake vent of the impeller-driven watercraft and attaches to a blade of an impeller of the impeller-driven watercraft, causing cavitation and imbalance, thereby slowing the impeller-driven watercraft.

An active automated anti-boarding device for a maritime asset security system includes a housing for mounting the device on a maritime asset. The deterrence device includes visual and sound deterrence emitters within said mount to disperse a directional fan pattern of sight and visual deterrence response outward from the housing to unauthorized boarders. An active automated anti-boarding maritime asset security system includes detection devices configured to mount to maritime asset, the detection devices each including emitters and receivers for generating and detection beams that form a virtual fence to form a detection network on a portion or around an entire maritime asset. Deterrence devices responsive to the interruption of the spaced apart detection beams produce a deterrent response that is non lethal. The deterrence response can be a law enforcement level of deterrence, it can induce discomfort and/or disorientation to deter unauthorized boarders. The deterrence response can be strong enough to cause physical pain in an authorized boarder.

An active automated anti-boarding device for a maritime asset security system includes a housing for mounting the device on a maritime asset. The deterrence device includes visual and sound deterrence emitters within said mount to disperse a directional fan pattern of sight and visual deterrence response outward from the housing to unauthorized boarders. An active automated anti-boarding maritime asset security system includes detection devices configured to mount to maritime asset, the detection devices each including emitters and receivers for generating and detection beams that form a virtual fence to form a detection network on a portion or around an entire maritime asset. Deterrence devices responsive to the interruption of the spaced apart detection beams produce a deterrent response that is non lethal. The deterrence response can be a law enforcement level of deterrence, it can induce discomfort and/or disorientation to deter unauthorized boarders. The deterrence response can be strong enough to cause physical pain in an authorized boarder.