Cross Sound Cable: A Short Submarine Link in the United States
The Cross Sound Cable is a submarine cable connecting
New Haven, Connecticut, to
Shoreham, New York, across Long Island Sound. With a length of 40 km, it is relatively short compared to many international submarine cables. Owned by the Cross Sound Cable Company, it has been listed as in service since 2003 according to GeoCables records.
What makes the Cross Sound Cable notable is its short distance and domestic nature, which contrasts with the transcontinental or transoceanic cables that dominate industry headlines. However, details about its design capacity, fiber pairs, supplier, and technology are not publicly disclosed, leaving some aspects of its specifications unclear. This lack of transparency is not uncommon for smaller or regional cables.
Quick facts
| Cable name | Cross Sound Cable |
| Length | 40 km |
| Ready for service | 2003 (GeoCables database value) |
| Owners | Cross Sound Cable Company |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing points | New Haven (United States); Shoreham (United States) |
| One-way light propagation | ≈ 0.2 ms |
| Theoretical RTT floor | ≈ 0.4 ms |
Route
The Cross Sound Cable spans Long Island Sound, connecting New Haven, Connecticut, on the northern shore to Shoreham, New York, on the southern shore. This corridor is entirely domestic and serves as a link between the northeastern United States' mainland and Long Island. The geography of Long Island Sound makes it a natural location for such a cable, as the waterway is relatively shallow and narrow compared to open ocean stretches, simplifying installation and maintenance.
Why it was built and what it carries
The Cross Sound Cable was likely constructed to enhance connectivity between Connecticut and Long Island, providing additional bandwidth and redundancy for regional telecommunications networks. While specific details about its traffic or usage are not publicly disclosed, cables of this type typically support internet, voice, and data services. Its short length and domestic scope suggest it is part of a broader regional infrastructure rather than a major international route.
History: what can be established
GeoCables lists the Cross Sound Cable as ready for service in 2003. This date aligns with the general timeline for many regional submarine cables built in the early 2000s to meet growing demand for internet and data services. If industry sources suggest a different year, such discrepancies could arise from delays in commissioning, regulatory approvals, or updates to operational status. However, no conflicting dates are currently known.
Capacity and technology
Public sources do not disclose the design capacity, number of fiber pairs, supplier, or specific technology used in the Cross Sound Cable. Without operator documentation, attributing these values would be speculative. Given its short length and domestic scope, it is likely less complex and lower in capacity compared to transoceanic cables, but this cannot be confirmed without further information.
Latency: the physics
The theoretical one-way light propagation time for the Cross Sound Cable is approximately 0.2 ms, with a round-trip time (RTT) floor of 0.4 ms over the wet segment. However, real-world latency is higher due to additional factors such as land tails, terminal equipment, and routing. GeoCables' live measurements from remote probes reflect full internet paths rather than the cable itself. For example, the minimum RTT from Saint Petersburg to New Haven was 114.7 ms, while Singapore to New Haven measured 226.2 ms. These values include terrestrial and other submarine cable segments, as well as internet routing inefficiencies.
Redundancy: what happens if it breaks
In the event of a failure, redundancy for the Cross Sound Cable would likely depend on other regional infrastructure connecting Connecticut and Long Island. While specific alternatives are not listed in the GeoCables database, the northeastern United States has a dense network of terrestrial and submarine cables. Repairing a short cable like this typically involves locating the fault, deploying specialized vessels, and replacing or splicing the damaged segment. Long Island Sound's relatively shallow waters make such operations less challenging compared to deep-sea repairs.
Bottom line
- The Cross Sound Cable is a 40 km submarine cable connecting New Haven, Connecticut, to Shoreham, New York.
- It has been listed as in service since 2003, according to GeoCables records.
- Details about its design capacity, fiber pairs, supplier, and technology are not publicly disclosed.
- Theoretical RTT over the wet segment is approximately 0.4 ms, but real-world latency is higher due to additional factors.
- Redundancy would rely on other regional infrastructure, and repairs are relatively straightforward due to the shallow waters of Long Island Sound.