In the past, countries would use warships to either defend their territories or attack another. Although the former is still true today, the naval warfare happens in grey zones as heightened tension occurs in their borders. They use vessel-stopping devices to avoid shooting vessels from other countries, which has proved challenging and calls for creative thinking.

Some examples of tensions between borders are that of Iranian boats harassing warships of the U.S. in the Persian Gulf and near-collisions with PLA vessels in the South China Sea. But in all these events, no one was shooting.

The main concern for these events is that any approaching boat might be a floating bomb like the one in 2000 that killed 17 sailors on board the USS Cole.


Vessel-Stopping Devices

The U.S. Navy developed SNARE, short for Small Naval Arresting Rope Entangler, in 2012 to fire a branching plastic rope that gets entangled to the propeller of any trespassing vessel. It is fired using a pneumatic launcher like the ones used to fire T-shirts. Moreover, the U.K. also has a similar system launched from a boat or dropped by a helicopter.

However, this system had two problems. First, it is difficult to untangle the rope from the propeller, which could require a diver, and the second is that the floating device is not environmentally friendly and could get tangled to another vessel later on.


The Hagfish Slime

The Surface Warfare Center of the U.S. Navy is developing a system that is based on hagfish slime. A hagfish looks like an eel that secretes a mucus-like substance that expands into a mass of slime when it is attacked, preventing the predators from catching them.

Surface Warfare Center's synthetic slime weapon is called the Vessel Stopping Occlusion Technology, which prevents a boat from moving, but disappears after a few minutes and does not leave any environmental residue, unlike the SNARE.


The Rubbery Octopus

There is also another Navy invention that targets jet skis patented last year. It looks like an octopus with a head and tentacles made of rubbery and biodegradable material that measures two to three inches across and several feet long. It is fired from a pneumatic launcher, or they could also be placed around a ship, which serves as a floating barrier.

This rubbery octopus will not cause any harm to the jetski, but it will only stop it. The jetski can be started up normally again once the barrier is removed.


The Torpedo

But for stations that require a more emphatic way of stopping a vessel, firing a non-lethal torpedo might be the best choice. Raytheon Company patented a Non-lethal naval vessel interdiction weapon in 2018 that loos like a torpedo but just without the explosive warhead.

Instead, it deploys a barbed harpoon through the hull of the target then closes the hole around it using a sealant to prevent or at least delay the sinking of the vessel. The weapon then opens a sea anchor or a parachute once it is secured to the target, creating enough drag to stop it from moving or get it to tangle with its propellers.

READ: Is China Building World-Class Military to Match the U.S.?


Why not just shoot them?

Vessel-stopping devices are not made to completely harm the target but rather just to make them stop. These types of weaponry may seem comical to most people but in a zone where there is an international conflict, escalating the situation by shooting and risking the other boats is the last thing a captain should do.

Using these types of weaponry, such as the rubber octopus, non-lethal torpedo, and some bomb may just provide the navy what they need to stop vessels from crossing their borders. Such devices ould allow the U.S. forces to continue their mission and, at the same time, preventing any broader conflicts from happening.

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