Editor’s Note: SubCableWorld and its sister publication Ocean News & Technology (ON&T) magazine joined forces recently to try something a little different.  We wanted to have a thought-provoking discussion highlighting the potential use of a new technology for an application that was not being discussed very much, if at all. 

With this backdrop, we thought we would approaching the concept of using uncrewed surface vessels (USVs) to monitor Cable Protection Zones (CPZs).  The potential for USVs to be used for various military patrol duties are being explored, but we were not aware of any efforts to look specifically at CPZ monitoring. 

Therefore, we decided to speak about the subject to a USV industry expert.  Basically, we asked if USVs be able to perform this task and if so, how would it be accomplished?  We hope you find this feature interesting and perhaps it will facilitate additional discussions of the subject.

The article below appears in the January 2022 issue of Ocean News & Technology under the title, Submarine Cable Protection: A USV Developer’s Perspective.  The magazine can be viewed by clicking here:


Submarine Cable Protection: A USV Developer’s Perspective

Submarine cables are designed and manufactured to withstand extreme forces, both environmental and manmade. As reliable as cable technology has become in recent decades, subsea cables do fail from time to time.

This can have disastrous consequences. Whether it be an intercontinental subsea fiber optic cable hosting an unfathomable volume of business and private communications traffic—including financial transactions—or a critical submarine power cable serving linking critical offshore energy infrastructure—such as an oil rig or wind turbine—the continuity of 21st Century life is intrinsically linked to efficient cable operations.

Protecting seabed cables has taken on even greater importance in the digital age. Many industries and institutions not only rely on connectivity these days; they dependent on it. Today, disruptions to Internet access can escalate to matters of national security. As a result, many countries are setting up Cable Protection Zones (CPZs) that prohibit anchoring or fishing – the activities most likely to cause damage – in areas where submarine cables are located. CPZs are monitored by several means: AIS, land-based radar, crewed patrol vessels, and even helicopters. 

As the greatest threats to submarine cables are in shallow water, these CPZs are relatively close to shore. While the distance from shore can vary considerably, some CPZs can extend outward to 50 nautical miles offshore, with varying widths several nautical miles across, and of water depth to 2,000 meters or more. 

As the submarine cable industry looks to realize ever greater efficiencies at sea, could USVs act as a cost-effective and practical solution for CPZ monitoring? ON&T sat down with a USV expert, SeaRobotics’ VP – Programs Lou Dennis, to assess the viability of uncrewed surface vehicles for such a task.


ON&T: Could USVs provide a low-cost alternative to the current methods for monitoring a CPZ? 


LD: Certainly. USVs are currently in use performing coastal mapping operations near shore which could easily be extended further offshore ad to the water depth of CPZs.


ON&T: Is the current state of USV technology adequate for this role? If not, what needs to happen to enable USVs to serve in this role?


LD: The USV technology needed is available today and is most deployed for hydrographic survey purposes and other such ocean science campaigns. The drive to streamline marine survey has been a big driving force for USV development over the past few decades. But we are seeing USVs being developed for a broadening range of applications, such as port and harbor security and surveillance. While much of the technology and design parameters of such vehicles is similar, the development of a fit-for-purpose vehicle is fundamentally dependent on a fully defined Concept of Operations (CONOPS). So, this would be the first step. The technology is available; the question is: how do we shape it to serve CPZ monitoring requirements?


ON&T: How would you see USVs working from an operational perspective?  What specific capabilities would the CPZ USVs need, and do they currently exist, or would they need to be developed? 


LD: Having detailed the CONOPS for a particular CPZ, the USV’s operations would be highly tailored. In terms of instrumentation, any USV would need to be outfitted with typical navigation aids, (Radar, INS, AIS, etc.), a suite of both visible light and infrared cameras, LiDAR, and a robust communications suite (wi-fi, VHF, Cellular, Iridium, Satellite Coms). It would need to be equipped with an advanced autonomy system to include obstacle detection, obstacle avoidance, and perception and response capability.

Also beneficial would be the ability to integrate and deploy a multibeam sonar, a sub-bottom profiler, and cable detection sensors to enable seabed surveys of the CPZ to determine any changes or disturbances to the cable or cable route. All these subsystems exist but have not necessarily been integrated into a specific purpose-built USV platform yet.


ON&T: What shore-based facilities would be needed to monitor and control the USVs?


LD: Operationally, it would make good sense to co-locate the land based USV operations hub near the cable landing site to store/maintain/charging/refueling the USV between monitoring watch cycles. A NOC (Network Operations Center) would also need to be staffed; however, it could be remotely located and not necessarily near or within the maintenance site.


ON&T: What would you consider the process of action if a USV spotted activity that could be in violation of the CPZ rules? What direct intervention, if any, could the USV take and what response would be initiated from the shore-based authorities? 


LD: Again, this links directly back to the CONOPS and the importance of specifying the operational objectives of the USV and the scope of activities covered by the proposed system. But if the primary mission of this uncrewed asset is to comb a defined area for other unauthorized vehicles within the CPZ, on detection of such an infringement if could:

  • Alert authorities: Sound an alarm, send an e-mail, or even make a phone call to notify the correct authorities of a violation within the CPZ
  • Sound a horn, turn on flashing lights and navigate to a proximity of the violating party and station keep awaiting further supervisory control from the shore-based NOC
  • Annunciate a verbal warning, instructions of violation and serve as an audible communication conduit between the violators and the CPZ authorities