The legal implications of submarine cables have been reviewed by the ITU/WMO/UNESCO Joint Task Force, which published a study in 2012. The topic has been further examined by the International Submarine Cable Protection Committee (ICPC), whose legal counsel, Kent Bressie, provided an excellent summary.
As these reports make clear, Submarine Cables and Marine Scientific Research (MSR) are governed under separate legal regimes, neither of which are clearly defined. Adding sensors to a preexisting cable or a new submarine cable installation project might suggest that it be governed as MSR, or, at least, encourage some parties to claim it as such. This classification, however, could be used as a justification to either prohibit the cable’s installation or to disrupt its operation once installed. So here we have a curious situation: by adding sensors in the name of securing valuable MSR—data pertinent to the cable’s own performance—we could, in fact, be making the cable less secure. This concern is clearly understandable and, as cable system operators err on the side of caution, has hindered more widespread investment in SMART cable technology.
To avoid dealing with these issues directly, the JTF accepts that the first SMART cables will be installed only within the Exclusive Economic Zones (EEZs) of participating nations. Later, when the technology is more fully proven, the JTF hopes to reopen a broader discourse.
To date, the discussion applies to cables with internal sensors. But what about the use of external sensors to monitor cables? Here we can assume that many of the same principles would apply, but given that the purpose of the monitoring is solely to protect the cables, and the monitoring is not intrinsic to the cables, the use of external sensors would be met with less objection. Deploying an autonomous vehicle over a cable route, even with active sonar, is deemed free navigation of the high seas; it is considered a legitimate shallow or deep-water monitoring system necessary for submarine cable maintenance. Further, monitoring within national zones of a particular country can be performed by operators within that country, so this also eliminates any concerns regarding sovereignty. Monitoring is performed independently of normal cable operations, so the cable should still be treated as if it were just a cable. We can begin to see how external monitoring could have advantages over internal sensors for the specific purposes of cable assessment and protection. External monitoring, however, is unable to offer the same capabilities as internal sensors for earthquake sensing and tsunami warning systems, but perhaps future scientific research could be carried out in conjunction with the external monitoring to help mitigate this.
How about technologies that don’t physically add anything to the actual cable, such as Distributed Acoustic Sensing (DAS)? This is a grey area. In the case where DAS is used closer to land in the first few repeater spans and the data is not disseminated, no one besides the cable operator is likely to even be aware that DAS is being used. In the case where a cable is used for seismic monitoring and the collected data are later published for research, some objections might be raised, as this clearly points back to the cable having been repurposed and used for MSR, even as it continues to carry telecom traffic. While this seems to be a specious and roundabout argument on which to rationalize an international incident, some small risk is undeniable. In cases where DAS is clearly and overtly used for cable protection, seismic monitoring, and whatever else can be gleaned from the acoustic environment around a cable, with data freely available to the science community, early warning centers and others, the situation is more akin to SMART and, as a result, cable systems are at risk of being classified as MSR.
Another question we might ask is could SMART functions be incorporated without being overt? Probably yes, but that would defeat one of the main purposes which is to provide widely available scientific data regarding the ocean environment. Sooner or later someone will make the connection that such and such a cable must be equipped with sensors.
In summary, from a legal and regulatory viewpoint, the whole topic of sensor enabled cables remains clouded with uncertainty. Sensors and monitoring which are used solely by the cable owner for the purposes of operations and maintenance are very likely to be acceptable. External monitoring of a cable cannot be prevented and may not even be tied directly to a particular cable, although monitoring in another country’s jurisdiction may be prohibited. Intrinsic sensors with widespread data dissemination will remain a concern and much further work is needed.
Read part 1 of the SMART Subsea Cables discussion: UN Tsunami Steering Committee Goes Virtual