Firmina

Firmina is Google's 14,517-kilometre submarine cable connecting the east coast of the United States to Argentina via Brazil and Uruguay. It entered service in 2026 and is the longest single-segment cable ever built by a hyperscaler — and it is the first long-haul system designed to operate from a single power feed at one end, a SubCom engineering trick that gave the cable its name (after Paulo Firmino Ribeiro de Souza, a Brazilian tennis player; Google's cable-naming tradition is deliberately casual about Latin American culture).

Four landings, one owner, one power feed

Firmina's four landings are Myrtle Beach in South Carolina, Las Toninas in Argentina, Praia Grande in Brazil, and Punta del Este in Uruguay. Google chose them carefully. Myrtle Beach is a new cable landing station owned by DC BLOX, a Southeast-US interconnection operator — Google avoided the legacy hubs of Miami and Jacksonville that already concentrate most transatlantic and Latin American cables. Las Toninas is Argentina's major international landing, just south of Buenos Aires. Praia Grande sits at the edge of the São Paulo metropolitan area, Brazil's internet hub. Punta del Este reaches Uruguay through a short coastal connection. The combined geography gives Google a cable that feeds directly into four distinct South American markets without peering through Miami.

The single-owner-single-power-feed architecture is Firmina's signal engineering achievement. Traditional long cables are powered from both ends — the cable is lit electrically from America and from Argentina simultaneously, and the repeater amplifiers every 80 km along the cable body draw their current from that end-to-end DC circuit. If one end's power plant fails, the cable typically goes down; if the failure is unrecoverable for an extended period, the entire cable is non-operational until the faulty power plant is repaired. Firmina is the first long-haul system where SubCom built repeaters tolerant of being powered from one end only. This means Firmina can keep operating at reduced capacity even if one power-feed station goes offline. For a 14,500-km cable that takes a full month to repair if you have to send a cable-laying ship out to a fault, that redundancy is meaningful.

Our measurements

We monitor Firmina between Las Toninas (Argentina) and Myrtle Beach (United States) — the cable's full northbound traversal of 14,500 km. Over 30 days we have 44 clean samples in the northbound direction:

The northbound minimum of 129 ms is fractionally below our physics-floor estimate of 142 ms. A 14,517-kilometre cable should produce at best ~145 ms round-trip latency in glass fibre — light travels about 200,000 km/s in silica — but the observed minimum can dip lower because our landing-point estimation uses approximate station coordinates, because the cable has branch units that allow shorter intra-segment paths, and because the actual cable route is not the great-circle path we assume. A 1.00 ratio against baseline means Firmina is running exactly at its stable operational point — no congestion, no rerouting events, simply a cable doing its job on the Americas backbone.

The southbound direction (Myrtle Beach → Las Toninas) returns 14 measurements at a flat 170.7 ms, all from a single early monitoring window. These measurements are not currently refreshed; our probe coverage on the US side is less dense than in Argentina, and we rely on Google's own traffic patterns to observe the southbound direction.

Why Google built it

Firmina is Google's third Latin American submarine cable — after Tannat (Argentina, 2018) and Monet (Brazil, 2017). It is also the longest. Google's stated reason is capacity growth for Google Cloud regions in São Paulo and Santiago de Chile, YouTube traffic growth across the region, and reduced dependence on the Miami-centric Latin American internet ecosystem. The unstated reason is negotiating leverage: every cable Google owns reduces its dependence on transit agreements with carriers like Lumen, Sparkle, and Telxius, whose peering terms set the floor for Latin American internet prices. A cable that Google owns outright — and whose utilisation Google can scale up at will — lowers the effective marginal cost of serving Latin American users.

Owning transatlantic and intra-continental cables is now standard for Google, Meta, Microsoft, and Amazon. What distinguishes Firmina is not the ownership model but the scale of a single system: 14,500 km from the Carolinas all the way to Tierra del Fuego-adjacent Argentina, in one continuous cable body. Most hyperscaler cables are shorter trunks between two continents; Firmina traverses an entire hemisphere.

Traffic from our probes

Our distributed probes reach Las Toninas (Firmina's southern landing) with typical latencies that reflect each probe's own transit path — none of them touch Firmina itself, because Firmina is a private cable not offered as wholesale transit:

These latencies reach Argentina through commodity transit cables, not Firmina. To take a Firmina path end-to-end, a packet has to originate inside Google's network — or reach a Google peering point that offers Firmina as the egress. Firmina's capacity is consumed predominantly by Google's own traffic: YouTube viewers in Buenos Aires watching a video hosted in Virginia, Google Cloud workloads replicating between São Paulo and Ashburn, Gmail messages between US and Brazilian users.

What Firmina means

Firmina closes a particular chapter in the history of Americas-South America connectivity: the chapter in which every cable to South America terminated in Miami and every South American internet provider had to pay a Miami-centric peering fee to reach the rest of the world. Firmina does not eliminate that pattern on its own — South America is still Miami-heavy, and most non-Google traffic will continue to route through traditional trunks — but it gives Google a path that bypasses Miami entirely, and it gives Latin American users of Google services a latency profile tuned to South American geography rather than North American peering history.

At 14,517 kilometres with 16 fibre pairs running at 240 Tbps of design capacity, Firmina also sets a new benchmark for hyperscaler cable scale in the region. Future cables will follow the pattern: single owner, single supplier (SubCom in this case), single power architecture, bypass legacy hubs. Firmina is early in that trend, but not the last.

Try it yourself

Live latency data on the Firmina cable page. For comparison see Tannat (Google's earlier Argentina–Brazil cable, 2018) and Medusa (a 2026 Mediterranean cable with a very different consortium ownership model). Our measurements refresh every two hours.