Sub Surface
Protection
Dynamic and static sub surface capabilities — stopping underwater intrusion from divers, manned submersibles, and unmanned underwater vehicles.
Complete sub surface protection — above and below the waterline
Vessel Arrest Sub Surface Protection addresses one of the most challenging threat vectors in maritime security: the underwater approach. The product range offers both dynamic rapid-deployment capabilities for active interception of underwater intruders, and static barrier solutions that integrate directly with existing Vessel Arrest Boom and Fence installations.
The range covers four distinct static system types — rope, webbing, stainless steel wire, and intelligent fibre optic detection — alongside the VARD-U rapid deployment system for dynamic underwater interdiction. All systems are designed for operational flexibility and can be tailored to site-specific threat profiles and environmental conditions.
Rapid deployment for active underwater interdiction
The VARD-U is a rapid deployment sub surface system designed to stop an underwater intrusion of divers or sub surface vehicles — manned or unmanned. It provides an active, deployable response capability for scenarios where a static barrier is not in place or has been bypassed, delivering a less-than-lethal means of stopping sub surface threats underway.
Four static sub surface systems — one integrated approach
Rope Systems
High-performance sub surface rope barrier providing entanglement protection for divers and underwater vehicles. Installed as a standalone system or integrated beneath the Vessel Arrest Boom or Fence.
Webbing Systems
Sub surface webbing barrier offering a wider entanglement net for comprehensive underwater protection. Configurable to depth and width requirements for the specific installation environment.
Stainless Steel Wire Systems
Heavy-duty stainless steel wire barrier for high-threat, permanent installations. Provides maximum structural resistance to forced entry and cutting attempts in demanding maritime environments.
Intelligent Cut Detection — Fibre Optic
The most advanced sub surface protection option. A fibre optic woven net that detects any cut or breach attempt and triggers an immediate alarm — described in detail in the section below.
Standalone or Integrated Installation
All static sub surface systems can be installed as an individual item or added directly to the Vessel Arrest Boom or Vessel Arrest Fence — providing seamless surface-to-seabed protection across the entire security perimeter.
Intelligent fibre optic intrusion detection
The VA-UID is a uniquely structured fibre optic system comprising a fibre optic woven net. Each fibre net zone is formed from a single woven fibre optic cable through which coded infrared light is continuously transmitted. Any cut in the cable breaks the light path and immediately triggers an alarm.
The net is generally comprised of two distinct sections: a lower section providing cut-through protection to the seabed, and an optional upper outrigger section. Any attempt to cut through or climb over the outrigger section will also trigger an alarm. Pressure sensitivity on the outrigger can be adjusted to balance security requirements against environmental conditions.
Coded Infrared Light Path
Continuous IR transmission through the cable — any breach instantly breaks the coded signal and triggers alarm.
Cut-Through & Climb-Over Detection
Dual-zone architecture protects against both bottom cutting and top climbing — two distinct intrusion vectors covered by one system.
Adjustable Pressure Sensitivity
The outrigger section pressure threshold is tunable — balancing security sensitivity against local environmental conditions such as current, debris, and marine life.
Sub surface protection in deployment