France 2030 Seabed Control Plan is 21st Century Version of the Atlantic Wall

France has unveiled new “Seabed Control” where they will have drones, mines, submarines and missile platforms to fortify their coastal defenses out to the bottom of the ocean.

This is somewhat like a 21st version of the Atlantic Wall or the Maginot Line. However, the new plan and having military vehicles that can go all the way to the seabed is useful. Submarines tend to not go below 500 meters in depth while the ocean bottom averages about 4250 meters deep.

Vehicles or devices that operate on the ocean floor will be very hard to detect. Think about the years and decades it takes to find wrecks on the bottom of the ocean. Small submarines and drones have already reached the bottom of the ocean.

Here is seafloor map of the Atlantic Ocean. There is all kinds of rough terrain.

The English channel / Straits of Dover are only about 50 meters deep. The seabed becomes really interesting new territory for military use when it is 500 meters or deeper and has rocky terrain or coral or other features. Basalt rock makes sonar and magnetic surveying very difficult. At less than 500 meters or with smooth sand, a drone or new mobile mine could dig in below the sand and hide.

The Atlantic Wall and Maginot Line were on top of the land sitting along the coastline or along a border. They were bunkers and guns built into the rock that could be bombed from the air or pounded by naval guns.

Holding the ocean bottom with enough force would mean that no ships or submarines would be able to operate safely above them. An attacking military would have to have its own ocean crawling force. They would have to come forward on the ocean floor hiding among jagged rocks and the equivalent of mountains and other ocean bottom terrain. The attacking force would take out the ocean floor defenders and defenses and allow submarines to then safely operate.

Ocean bottom terrain is somewhat like operating in the mountains. Mountain forces can hide from attacks using hundreds of meters of rock.

The French Navy already has mine warfare and hydro-oceanography capabilities contributing to the control of the seabed. France will expand capacities down to 6,000 meters deep with deep-sea exploratory military capacities. They will use underwater drones (AUV – Autonomous underwater vehicle) and robots ( ROV – Remotely operated vehicle).

Some of France’s new plans are:
Study the particular modes of ultra-low frequency acoustic propagation.
Increase our undersea search, surveillance and intervention capabilities to meet the needs inherent in maintaining freedom of action for French forces in areas with depths down to 6,000 meters.
Continue to analyze ways of deploying underwater surveillance vehicles in order to broaden the range of military options: air-portability, combat ships, submarines, etc.
Make CEPHISMER a center of expertise capable of implementing a military capability complementary to SLAMF for depths greater than 300 meters.

China the UK are also working on seabed defense systems.

Today’s submarines are link blimps in the ocean. They float high over the seafloor. Dr Robert Ballard proposed submarines that hide on the ocean floor.

Modern nuclear attack submarines like the American Seawolf-class are estimated to have a test depth of 490 meters (1,600 ft), which would imply a collapse depth of 730 meters (2,400 ft). Each 10 meters (33 feet) of depth puts another atmosphere (14.7 psi/100 kPa) of pressure on the hull.

There is a lot of sonar and magnetic interference on the ocean floor. It can be very hard to find something hiding in the seafloor terrain.

The average ocean depth is 4250 meters (2.6 miles).

300 meters (1,000 feet): the hull is withstanding thirty atmospheres (30 bar, 441 psi, 3,000 kPa) of water pressure.
800 meters: the hull is withstanding eighty atmospheres (80 bar, 1176 psi, 8,000 kPa) of water pressure.
3000 meters: hull is withstanding three hundred atmospheres (300 bar, 4410 psi, 30,000 kPa) of water pressure.
6000 meters: hull is withstanding six hundred atmospheres (600 bar, 8820 psi, 60,000 kPa) of water pressure.

SOURCES – Naval News
Written By Brian Wang,