Beneath the ocean lies a network that makes the internet possible. These aren’t satellites or radio towers—just hair-thin strands of glass stretching thousands of miles across the seafloor. Subsea fiber optic cables carry over 95% of global internet traffic, enabling everything from FaceTime calls to billion-dollar banking transactions. But some of these cables aren’t just functional—they’re engineering marvels. Here are 8 of the coolest subsea fiber cables on Earth, and exactly what they do.
🌊 MAREA (U.S. to Spain)
Built by: Microsoft, Meta (Facebook), Telxius, and Equinix
Length: ~6,600 km (4,100 miles)
Capacity: 200+ terabits per second (Tbps)
MAREA isn’t just fast—it was built to break records. Laid between Virginia Beach, USA and Bilbao, Spain, MAREA was designed to be resilient, scalable, and low-latency. When it launched in 2017, it was the highest-capacity transatlantic cable in the world—and it’s still among the top performers today.
- MAREA sits farther south than most transatlantic routes, providing geopolitical diversity and more stable uptime in case of disruptions elsewhere.
- It uses an open system design, allowing rapid upgrades without needing to replace the cable itself.
- Meta uses it to power Europe–U.S. traffic for Instagram, Facebook, and WhatsApp.
- Microsoft leans on it for Azure cloud data moving between continents.
This cable proves that big tech isn’t just building apps—they’re building the physical internet itself.
🌍 2Africa (Circle Around Africa)
Built by: Meta, China Mobile, Orange, Vodafone, and others
Length: Over 45,000 km (~28,000 miles)
Capacity: 180 Tbps (estimated)
2Africa is one of the largest subsea cable projects ever attempted. Designed to wrap around the African continent, it connects over 33 countries across Africa, Europe, and the Middle East.
- It forms a near-complete ring that improves connectivity, redundancy, and resilience in regions that historically suffered from limited infrastructure.
- Countries like Nigeria, Kenya, and South Africa will gain high-speed connectivity to Europe, the Middle East, and even India.
- 2Africa uses SDM1 (space-division multiplexing), which allows more fiber pairs than older designs—boosting data capacity without adding new cables.
Once complete, 2Africa is expected to triple internet capacity in Africa, helping to close the digital divide across the continent.
🌐 Dunant (U.S. to France)
Built by: Google
Length: ~6,600 km (4,100 miles)
Capacity: 250 Tbps (record-breaking at launch)
Named after Henri Dunant, founder of the Red Cross, Google’s Dunant cable made headlines when it launched in 2020 with an astounding 250 terabits per second capacity—the highest ever for a transatlantic cable at the time.
- It connects Virginia Beach, USA to Saint-Hilaire-de-Riez, France, forming a core part of Google’s private network.
- Dunant was the first cable to use space-division multiplexing (SDM) on this scale—enabling multiple fiber pairs and greater efficiency.
- It supports key Google services like Search, YouTube, Google Cloud, and Gmail by ensuring low latency and ultra-high reliability across continents.
This cable showcases how tech giants are no longer just leasing bandwidth—they’re building their own international infrastructure to support global platforms and future technologies like AI and AR.
🌏 SEA-ME-WE 6 (Southeast Asia–Middle East–Western Europe)
Built by: Telecom Egypt, Singtel, Bharti Airtel, Orange, and others
Length: ~19,200 km (~11,900 miles)
Capacity: 120 Tbps+ (designed for growth)
SEA-ME-WE 6 is the latest addition to a legacy of cables connecting Asia to Europe through the Middle East, following the paths of earlier SEA-ME-WE systems. It’s built to meet massive bandwidth demand from cloud providers, governments, and telcos along a densely populated corridor.
- It connects Singapore, Malaysia, Bangladesh, India, UAE, Egypt, and France, with many branch landings along the way.
- The route is designed for high resilience and geopolitical flexibility, giving multiple countries access to backbone-grade bandwidth.
- It uses cutting-edge SDM technology to prepare for future bandwidth upgrades without replacing infrastructure.
SEA-ME-WE 6 helps anchor the digital future of South and Southeast Asia, acting as a bridge for cloud computing, AI services, and booming e-commerce across continents.
🌍 Grace Hopper (U.S. to U.K. and Spain)
Built by: Google
Length: ~6,250 km (~3,900 miles)
Capacity: 350 Tbps (across 16 fiber pairs)
Named after legendary computer scientist Rear Admiral Grace Hopper, this cable is one of Google’s most ambitious European infrastructure projects to date. Launched in 2022, it connects the U.S. (New York) to the U.K. (Bude) and Spain (Bilbao).
- It features 16 fiber pairs, a major leap from traditional designs, and supports space-division multiplexing (SDM) to maximize performance.
- It’s the first subsea cable to directly link the U.S. and Spain—giving Google more flexibility in routing European traffic.
- The Spain landing ties into Google’s broader plans to expand its cloud footprint in Southern Europe, especially with new data centers in Madrid.
Grace Hopper reflects the increasing need for cloud-first infrastructure—where fiber cables are not just about moving traffic but feeding entire cloud ecosystems in real time.
🌊 Equiano (Europe to Africa via West Coast)
Built by: Google
Length: ~15,000 km (~9,300 miles)
Capacity: 144 Tbps (with upgrade potential)
Named after Nigerian-born writer and abolitionist Olaudah Equiano, this cable is a game-changer for West African connectivity. Completed in 2023, it links Portugal to South Africa with landing points in Nigeria, Togo, Namibia, and more.
- It’s the first subsea cable to incorporate optical switching at the fiber pair level, allowing operators to independently manage their bandwidth—improving cost-efficiency and customization.
- In countries like Nigeria, Equiano is expected to triple internet speeds and reduce prices by over 20%, according to regional ISPs.
- It’s part of Google’s broader push to boost digital infrastructure in underserved regions, particularly in Africa’s rapidly growing tech markets.
Equiano doesn’t just move data—it helps level the digital playing field, enabling local innovation and more equitable access to cloud services.
🌐 Hawaiki Cable (U.S. to Australia and New Zealand)
Built by: Hawaiki Submarine Cable LP
Length: ~15,000 km (~9,300 miles)
Capacity: 67 Tbps (initial design, upgradable)
Completed in 2018, the Hawaiki Cable is a major transpacific system connecting Oregon (U.S.) to New Zealand and Australia, with branching units to American Samoa, Hawaii, and other Pacific Islands.
- It was the first independent cable system to directly link the U.S. to New Zealand and Australia—not owned by a major telco or tech giant.
- It has been credited with reducing latency and lowering bandwidth costs for Oceania, helping enable faster connectivity, cloud services, and better access to international markets.
- Hawaiki also promotes Pacific Island digital inclusion, providing connections for remote islands that previously relied on slower satellite links.
In a region historically underserved by robust infrastructure, Hawaiki was a transformative leap forward.
🌏 SJC2 (Southeast Asia–Japan Cable 2)
Built by: China Mobile, NTT, Singtel, Tata Communications, and others
Length: ~10,500 km (~6,500 miles)
Capacity: 144 Tbps+
Launched in 2022, SJC2 strengthens connectivity between Singapore, Thailand, Vietnam, Hong Kong, Taiwan, Japan, and the Philippines. It supplements the original SJC system, adding capacity and redundancy to one of the most bandwidth-hungry regions in the world.
- It’s built to handle skyrocketing demand from streaming, gaming, fintech, and cloud services in Southeast Asia.
- SJC2 integrates advanced technologies like space-division multiplexing and open cable architecture to allow easier upgrades in the future.
- It’s also designed with disaster resilience in mind, with alternative routes to bypass earthquake zones and congested maritime chokepoints.
SJC2 helps anchor Asia’s digital future, reinforcing the region’s role as a tech and data powerhouse.
From cutting-edge cables built by tech titans to projects designed to close the digital divide, subsea fiber is the unseen hero of our connected world. While satellites may steal the spotlight, it’s these quiet cables beneath the ocean that carry 95% of all global data traffic. Whether powering a video call, financial transaction, or your next cloud backup—one of these marvels is almost certainly involved.
And with new cables launching every year, this underwater network is only getting smarter, faster, and more inclusive.
