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Fibre optic undersea cables. Where, who, how and what?

Fibre optic undersea cables. Where, who, how and what?

By now it should be safe to say that you have definitely heard of fibre. No not the fibre you eat but rather the fibre internet that helps you order something to eat. Well, if you are still unsure about the fibre internet I am referring to, let me start at the beginning, by explaining fibre optic undersea cables.

What are fibre optic undersea cables and where are they?

Fibre optic undersea cables are a very advanced way of transferring data across the world in the ‘blink of an eye‘. These cables consist of extremely small ‘lines’ that transfer data via pulses of light. These lines of fibre optic are made up of extremely thin wires just a bit thicker than a needle. If you had to look at one of these fibre optic cables, it would almost look like a tiny glass or plastic tube. However, due to the sensitivity of such cables, they are often protected and insulated by multiple layers of hard materials such as metal and rubber. This is done to protect the cables from any potential force that may break the fibre optic cable.

There are of course fibre optic cables running under and next to most roads and houses bringing the joy of fibre internet connectivity to users all over the country. But how do those cables connect to the other side of the world? Well, those cables eventually meet stations which are connected to undersea fibre optic cables that run along the coast of Africa. If you are interested in seeing the cables that already exist just click here. This map shows you the world’s entire undersea fibre optic cable network as well as all the cables that are connected to Africa. The cables that run on the floor of the ocean are known as submarine cables.

Fibre optic undersea cables.
Fibre optic cables are laid undersea

There are currently five main submarine cables off the West Coast of South Africa:

1. Equiano Cable:

This cable is owned by Google.

2. West African Cable System (WACS):

This is owned by a multitude of telecommunications companies and spans a total distance of 14,530km. This cable connects 15 countries and starts in South Africa with its end point located in London.


This cable is also owned by numerous companies and spans a total distance of 14 350km. This cable connects South Africa to Portugal and Spain as well as several other African countries.

4. Africa Coast to Europe:

Once again and not surprisingly so, this cable is also owned by multiple companies. This cable runs a lengthy 17,000 km from South Africa to Europe.

5. 2Africa:

The most impressive of all the undersea fibre optic cables is the 2Africa. Owned by many, but most notably Facebook, MTN Group and Vodafone, the 2Africa cable runs a whopping 37,000km along the ocean floor. The cable will be fully operational by 2023. It will connect 23 countries around the world and will offer improved performance as well as cost effectiveness.

Along the East Coast of South Africa there exists an additional three submarine cables:

1. SAFE:

Connecting South Africa to India and Malaysia. The undersea fibre optic cable runs a total length of 13,500km.

2. Melting pot Indian-oceanic Submarine System (METISS):

Connecting South Africa to Mauritius and Reunion. This cable spans a distance of 3 200km.

3. Eastern Africa Submarine System (EASSy):

Botswana Fibre Networks and Telkom South Africa are two of many owners. The cable runs a length of 10,500km.

How and who lays these fibre optic undersea cables?

As you can see, there are many fibre optic undersea cables running along the coast of South Africa. One begins to think, how long does it take to lay these cables and how do they lay cables that are on average 10 000km in length.

Specially modified ships are used to lay the cable. The modern-day ships can lay around 200km of fibre optic cable per day and can carry around 2,000km of cable on board. Optical repeaters are installed along the line to ensure the strength of the data pulse does not diminish over vast distances. The public knowledge as to the exact location of the cables is kept to a minimum as terrorists often like to destroy the cables and hold the companies ransom in return for the cessation of the cable destruction.

The average project cost of laying undersea fibre optic cables is around $100-$500 million (that’s US). This is much more cost effective than using satellites when you compare the rate of data transfer, which is much higher with cable than what a satellite can handle, for the same price.

Video on an undersea cable-laying vessel
How and who lays these fibre optic undersea cables?
Fibre optic cables are laid by specially equipped boats.

Remember the damaged WACS undersea fibre cable?

Early during 2020, South Africa experienced a submarine cable-break off the coast of South Africa. With that came slow fibre internet speeds and frustrated fibre internet clients. Many fibre internet service providers spent a fortune of money buying additional bandwidth to provide their customers with some sort of solution.

However, the speeds were still too slow for the number of users using fibre internet, especially during lockdown. The frustration levels grew and the repairs to the cable took extremely long due to the repair ship not being able to leave the port because of bad weather.

RocketNet (that’s us) however was still able to provide internet to the coastal customers by utilising another cable. We came up with another solution and simply directed the Cape Town traffic back to Johannesburg and from there used Seacom to breakout the internet.

That’s one of the reasons we rock!

Happy surfing!