A group of technology companies has applied for permits to build a hub near the beach in Carlsbad that would connect the United States with New Zealand and Australia via fiber-optic cables stretching more than 7,000 miles under the sea. Submarine cables carry huge streams of data such as video, tele phone calls and virtually anything on the internet at close to the speed of light. They have many times the bandwidth of satellites, and carry more than 95% of all international communications. The Carlsbad cables would come ashore underground and enter a 100-square-foot vault to be installed on land owned by the state Parks Department just east of Carlsbad Boulevard, north of Palomar Airport Road. From there, a trenched conduit would carry the cable to a connection about 3 miles inland, where the companies involved will occupy a now-vacant industrial building. “By utilizing the latest developments in submarine cable technologies, we have designed the longest, continuous optical subsea cable path in the world,” said Bevan Slattery, founder and co-CEO of SubCo, an Australian company that will operate the system, in a January news release announcing the project. The finished international cable system is expected to be the first to land in San Diego County. The additional cable capacity will help Australia accommodate the expected growth in its artificial intelligence, or AI, companies, Slattery said. It is one of several undersea cable systems that tech companies have installed or planned connecting the United States to Asian Pacific destinations, including Japan, Singapore and Guam. Los Angeles approved a cable hub at Dockweiler State Beach in 2024 for the Trans-Pacific Telecommunications Cable, a system connecting to Indonesia and Singapore. Other systems have been completed with connections in Northern California and the Pacific Northwest. A new undersea fiber optic cable linking Australia tothe United States is expected to come ashore at a hub proposed in Carlsbad. Starfish Infrastructure Inc. and Elkhorn Enterprises LLC have applied to Carlsbad and to other government agencies for permits to bring four fiber-optic cables from a point 3,000 feet offshore to the onshore hub in Carlsbad, states a report prepared by city officials. Both companies are subsidiaries of Google, according to the Federal Communications Commission. The cables are part of what’s called the Honomoana Project, named for the Polynesian words for “link” and “ocean.” Another company, Vero Networks, has applied for permits to install 4.3 miles of fiber-optic cable from the onshore hub in an underground conduit that will follow the public right-of-way along Palomar Airport Road and Yarrow Drive to an office building owned by Elkhorn Enterprises at Cosmos Court, near El Camino Real, according to the city report. The proposed construction needs a right-of-way permit from the city that could be approved administratively by staffers without a presentation to the Carlsbad Planning Commission or City Council. However, the city has determined that the project also needs a coastal development permit, which requires a public hearing before the Planning Commission. The Planning Commission’s decision is expected by the end of this year and is final unless appealed to the City Council. “There are multiple agencies that require review and approval of the Honomoana Project,” the city report states. “The state Lands Commission, who is the overall project lead, is preparing the environmental document for the overall project in compliance with the National Environmental Policy Act and the California Environmental Quality Act.” The undersea cable is expected to be operational by the end of 2028 between California and Australia, with branch links to Hawaii and Fiji to be added in 2029, according to the SubCo plans. One trade journal estimated the construction costs at $471 million. An uncrewed vessel deployed in early February from Australia began a remote survey of the seafloor cable route, according to the online magazine Business Today. The remote boat has a range of 2,000 miles and can go up to 15 days without servicing, which improves efficiency and reduces risk for operators. The ship that will install the cable will be a larger, specialized vessel carrying a crew of technicians and experts. As much as 60 miles of cable a little thicker than a garden hose will be loaded onto a turntable on the deck, where it can be unspooled as the ship advances along the route. The turntable will be reloaded and the long sections of cable will be spliced together aboard the ship as it advances. In shallower waters, the boat pulls a plow-like device that opens a trench in the seabed to bury the cable and protect it from things such as a boat anchor. In deeper waters, the line is laid directly on the seabed. Aside from stirring up sediment during the installation, there appears to be little danger to the environment. “Once deployed (the undersea cables) don’t make noise or pollute the ocean,” said Mark Zumberge, a research geophysicist in the Institute of Geophysics and Planetary Physics at Scripps Institution of Oceanography in La Jolla. “Frequently they are buried in the sediment within a few miles of shore and beyond they are laid on the seafloor,” Zumberge said in an email. “There is, of course, construction activity onshore near the coastline during installation,” he said. “Often, a directionally drilled borehole from the shoreside crosses the coast, emerging offshore some distance to get the cable past the surf zone and away from near shore boat anchoring.” Undersea cables can have other benefits in addition to transmitting huge streams of data. “Earth, ocean, and biological sciences are beginning to make significant gains … because we’ve learned how to detect earthquakes, temperature changes, whale sounds, and all sorts of things remotely using the cables,” Zumberge said. “The … methods are ever advancing, so from a scientific standpoint, adding more subsea cables is a good thing. “There is a movement led by Bruce Howe at the University of Hawaii to convince cable companies to add sensors to their cables for scientific purposes,” Zumberge said. “This is more expensive than the developing methods that just use fluctuations in the light traveling through the cables to sense disturbances along the cables’ lengths.” The cables are expected to last 25 years or longer, although the pace of technology rapidly increases capacity and can make older cables obsolete before that. Undersea communications cables are hardly new. The first trans-Atlantic copper cable was a telegraph line installed in 1858 between the United States and Britain, according to history.com. Queen Victoria used the wire to congratulate President James Buchanan on the accomplishment, widely considered an engineering marvel at the time. However, after a few weeks, the line stopped working, and it was another eight years before a more reliable link was in place. There were 570 in-service submarine cable systems globally as of February 2025, with plans in progress for 81 more, according to the trade publication TeleGeography. ...read more read less