Our most vital data network lies beneath the waves

By: Mike Hollands

The critical role that subsea cables play in our social and economic lives often goes unnoticed, but they do all the heavy lifting in high-speed international communications

In 1858, the first transatlantic cable was laid between Newfoundland and Valentia Island, Co Kerry, enabling transatlantic communications.

One hundred and sixty-three years later, it is easy to forget about Subsea cables’ role in Irish economic growth.

Just consider:

  • Subsea fibre optic cables transfer 99% of transoceanic data, operating at the speed of light, globally.
  • They are the physical structures which enable international connectivity in virtually all areas of our lives, including internet access, video calls, working from home, content-streaming services, and crucially, time-critical transactions.
  • Subsea cables are more reliable than satellite communication, allowing for a larger capacity of data transfer with enhanced levels of security.

What you also may not realise is the importance of rapid data and communication, which is facilitated by these subsea cables in helping organisations adapt to the disruption of Covid-19, which has fundamentally changed how we work, our communications and even our entertainment.   Microsoft reported it recorded more than 4.1 billion minutes of Microsoft Teams meetings in a single day and declared “we’ve seen two years’ worth of digital transformation in two months”.

We now operate in a rapidly evolving digital world, driving further demand for these cables as individuals and organisations become increasingly reliant on subsea cable’s exceptional data speed and capacity. In fact, this connectivity will be pivotal to Ireland’s success in attracting international companies in the technology, pharmaceutical and financial sectors.

The subsea cable industry greatly contributes to the Irish economy across many sectors. The draft National Marine Planning Framework reported that subsea international networks make Ireland an attractive region for investment for the technology and digital sectors. Telegeography state that there are twelve existing subsea cables connecting Ireland to the US and UK, and a further four systems are under development.  The government’s statement on the Role of Data Centres in Ireland’s Enterprise Strategy identified Ireland as a location of choice for many different sectors reliant on digital and telecommunications capabilities, all of which in turn rely on subsea cable interconnectivity.


Subsea cables are of strategic importance to Ireland’s future as a catalyst for economic and societal prosperity.