[2][3] After William Cooke and Charles Wheatstone had introduced their working telegraph in 1839, the idea of a submarine line across the Atlantic Ocean began to be thought of as a possible triumph of the future.

Gutta-percha, the adhesive juice of the Palaquium gutta tree, was introduced to Europe by William Montgomerie, a Scottish surgeon in the service of the British East India Company.

[9] In 1849, Charles Vincent Walker, electrician to the South Eastern Railway, submerged 3 km (2 mi) of wire coated with gutta-percha off the coast from Folkestone, which was tested successfully.

[7]: 192–193 [10] However, the experiment served to secure renewal of the concession, and in September 1851, a protected core, or true, cable was laid by the reconstituted Submarine Telegraph Company from a government hulk, Blazer, which was towed across the Channel.

The submarine cables were an economic benefit to trading companies, because owners of ships could communicate with captains when they reached their destination and give directions as to where to go next to pick up cargo based on reported pricing and supply information.

As early as 1816, Francis Ronalds had observed that electric signals were slowed in passing through an insulated wire or core laid underground, and outlined the cause to be induction, using the analogy of a long Leyden jar.

Thomson designed a complex electric-field generator that minimized current by resonating the cable, and a sensitive light-beam mirror galvanometer for detecting the faint telegraph signals.

By the 1890s, Oliver Heaviside had produced the modern general form of the telegrapher's equations, which included the effects of inductance and which were essential to extending the theory of transmission lines to the higher frequencies required for high-speed data and voice.

[37][38] The optic fiber used in undersea cables is chosen for its exceptional clarity, permitting runs of more than 100 kilometres (62 mi) between repeaters to minimize the number of amplifiers and the distortion they cause.

[citation needed] As of 2012, operators had "successfully demonstrated long-term, error-free transmission at 100 Gbps across Atlantic Ocean" routes of up to 6,000 km (3,700 mi),[41] meaning a typical cable can move tens of terabits per second overseas.

While in theory, a great circle route (GCP) between London and New York City is only 5,600 km (3,500 mi),[43] this requires several land masses (Ireland, Newfoundland, Prince Edward Island and the isthmus connecting New Brunswick to Nova Scotia) to be traversed, as well as the extremely tidal Bay of Fundy and a land route along Massachusetts' north shore from Gloucester to Boston and through fairly built up areas to Manhattan itself.

The type of optical fiber used in unrepeated and very long cables is often PCSF (pure silica core) due to its low loss of 0.172dB per kilometer when carrying a 1550 nm wavelength laser light.

[52][53][54][55] SLTE (Submarine Line Terminal Equipment) has transponders and a ROADM (Reconfigurable optical add-drop multiplexer) used for handling the signals in the cable[56][57] via software control.

Accordingly, the Australian Communications and Media Authority (ACMA) has created protection zones that restrict activities that could potentially damage cables linking Australia to the rest of the world.

[81][73][84][87][88] The cable break was declared a “national crisis,” and repairs took several weeks, leaving Tonga largely isolated during a crucial period for disaster response.

The remoteness of these cables in international waters, poses significant challenges for continuous monitoring and increases their attractiveness as targets of physical tampering, data theft, and service disruptions.

[101] Such sea passages are often marked as ‘maritime choke points’ where several nations have conflicting interests, increasing the risk of harm from shipping activities and disputes.

[72] Other proposed solutions include spatial modelling through protective or safety zones and penalties,[86][102][99] increasing resources for surveillance,[101] and a more collaborative approach between states and the private sector.

The most ambitious efforts occurred in World War I, when British and German forces systematically attempted to destroy the others' worldwide communications systems by cutting their cables with surface ships or submarines.

[113] During the Cold War, the United States Navy and National Security Agency (NSA) succeeded in placing wire taps on Soviet underwater communication lines in Operation Ivy Bells.

These agreements can help bridge the jurisdictional ambiguities and often resulting enforcement gaps in international waters, which ultimately hinder effective protection and are frequently exploited by organized crime.

[83] Given the central role of private companies in cable ownership, some experts also underscore the need for stronger collaboration between governments and tech firms to pool resources and develop more innovative security measures tailored to this critical infrastructure.

[114] Several media outlets and organizations indicate that Russian fishing vessels, particularly in 2022, passed over a damaged submarine cable up to 20 times, suggesting potential political motives and the possibility of hybrid warfare tactics used from Russia's side.

[120][83][88][94] In light of Nord Stream pipelines sabotage in the Baltic Sea, where subsea infrastructure vital to Germany and Russia was physically destroyed, and other incidents there, NATO has increased patrols and monitoring operations.

[84] Many countries lack explicit legal provisions to criminalize the destruction or theft of undersea cables, creating jurisdictional ambiguities that organized crime can exploit.

[83][87][102] Other legal frameworks, such as the 1884 Convention for the Protection of Submarine Telegraph Cables are outdated and fail to address modern threats like cyberattacks and hybrid warfare tactics.

In the Arctic, the absence of a central international authority to oversee submarine cable protection and the reliance on military organizations like NATO hinders general coordinated global responses.

[123] The legal challenges of protecting submarine cables from organized crime have resulted in recommendations ranging from treaty amendments to domestic law reforms and multi-level governance models.

[87] Enforcement issues could be tackled by aligning domestic laws with UNCLOS, implementing national response protocols, and creating streamlined points of contact for cable incidents.

The benthic zone is the ecological region at the bottom of the sea where benthos, clams and crabs live, and where the surface sediments, which are deposits of matter and particles in the water that provide a habitat for marine species, are located.