Fibre-optic Link Around the Globe (FLAG) is a 28,000-kilometre-long (17,398 mi; 15,119 nmi) fibre optic mostly- submarine communications cable that connects the United Kingdom, Japan, India, and many places in between. The cable is operated by Global Cloud Xchange, a former subsidiary of RCOM. Meta is building something massive — Project Waterworth, a subsea fiber-optic cable stretching 50,000 km across five continents. That's longer than Earth's circumference. and it could cost up to $10 billion. What Makes It Special Scale: 24-fiber-pair capacity, far bigger than most existing cables. A submarine communications cable is a cable laid on the seabed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The high-capacity, fiber-optic cable that will link five continents will span a fantastic 31,000 miles (50,000 km) – for reference, the circumference of the Earth is 24,901 miles. The exchange of data in the blink of an eye has become a given in much of the world – and yet we rarely pause to think about what makes it all possible: a complex global network of cables in the depths of the ocean that silently connects us. In the modern information age, undersea cables have.