The Firmina subsea cable spans 14,517 kilometers (9,020 miles), connecting the East Coast of the United States to Las Toninas, Argentina, with additional landings in Praia Grande, Brazil, and Punta del Este, Uruguay. The Firmina subsea cable is the first U.S. system with a direct landing in Uruguay and one of the few subsea cables connecting the United States with Argentina – beyond GlobeNet (via Malbec), SAm-1, and SAC.

The Firmina cable is named after Maria Firmina dos Reis (1825 - 1917), a Brazilian abolitionist and author whose 1859 novel, Úrsula, depicted life for Afro-Brazilians under slavery. A mixed-race woman and intellectual, Firmina is considered Brazil’s first novelist. 

The Firmina cable system is privately owned and invested by Google through its subsidiary GU Holdings Inc, being the landing party and contracted with DC BLOX, Telxius, ANTEL and Lumen as landing service providers for the following Cable Landing Stations:

• Myrtle Beach CLS: a new cable landing station in Myrtle Beach, South Carolina, owned by DC BLOX.
• Praia Grande CLS: an existing cable landing station in the city of Santos, Brazil, owned by Telxius.
• Punta del Este CLS: a new cable landing station in Punta del Este, Uruguay, owned by ANTEL (Administración Nacional de Telecomunicaciones), a state-owned operator in Uruguay. In December 2022, the President Luis Alberto Lacalle Pou formally approved Google to land and operate the Firmina submarine cable in the country, following an inspection of almost two years.
• Las Toninas CLS: an existing cable landing station in Las Toninas, Argentina, owned by Lumen Technologies through its subsidiary CenturyLink Argentina S.A.  Las Toninas is located about 160 miles south of Buenos Aires.

The Firmina cable system consists of the following segments:

• Main Trunk: from Myrtle Beach, South Carolina, to Las Toninas, Argentina, with 16 fiber pairs and a cable length of 13,413 kilometers (8,334 miles ).
• Brazil Branch: from a branching unit  to Praia Grande, Brazil (state of São Paulo), with 24 fiber pairs and a cable length of 580 kilometers (360 miles).
• Uruguay Branch: from a branching unit to Punta del Este, Uruguay, with 12 fiber pairs and a cable length of 524 kilometers (326 miles).
• Two Stubbed Branches:
  • one points towards Puerto Rico or the Dominican Republic and located on the high seas, with 12 fiber pairs
  • the other points towards Fortaleza, Brazil and located in Brazil’s exclusive economic zone (EEZ), with 16 fiber pairs

The Firmina cable system will have a total system capacity of 240Tbps for its 16-FP main trunk, or 15 Tbps per fiber pair.

SubCom is the supplier of Firmina cable project.

The Firmina cable system is expected to be ready for service by the end of 2023.