Marine Security Barrier - Underwater Security Technologies

A waterside perimeter is the one boundary that most sites simply leave open. Fences stop at the waterline, cameras see the surface and nothing below it, and the approach that matters most — underwater, at night — is the one nothing is watching.

A barrier that is also the sensor

MARINET is a fiber optic, cut-through detection underwater security barrier: an alarmed anti-swimmer, anti-diver and anti-frogman net that protects both above and below the waterline. The critical design decision is that the net itself is the sensor. It is built as a crisscross array, so there is no gap between detection points — no spacing between sensor heads that a diver can pass through undetected.

Why the distinction matters

Most underwater detection is either sonar, which detects a swimmer somewhere in a volume of water and struggles in cluttered harbors, or a physical barrier, which delays but does not report. Marinet is both at once: an intruder who attempts to cut through, climb over or pass under the barrier generates an alarm at the point of the attempt.

Where marine barriers are specified

Port facility security plans, naval and coastguard berths, LNG and fuel terminals, water intakes for power generation, and any waterside asset where the standard requires the water approach to be addressed rather than assumed. If you are writing to a port facility security plan, the requirement is usually explicit about the seaward side.