Doctrinally, the concept of amphibious operations has followed a deliberate linear approach from planning to termination with the landing force only entering the area of operations once rehearsal and re-embarkation have been completed to suit the requirements of the planned mission. As an example, the Royal Navy plans to deploy two Littoral Strike Groups (LSG) on a permanent basis, to extend the UK’s presence, insight, and influence globally. The most likely operating areas are the Indo-Pacific and North Atlantic Oceans. The forces are far more likely to be operating in the eventual amphibious operating area before an operation is conducted. In our view, the familiar acronym PERMSAT (Planning, Embarkation, Rehearsal, Manoeuvre, Shaping, Action, Termination) will be compressed to chronologically and geographically to three broad activities: persistent presence and posture; concentration of amphibious force, action and termination. But they will overlap and compete for resources and space. So how could the LSG maintain its situational awareness (and a degree of presence) while it must depart a littoral zone to reorganise and rehearse?
Advance force and pre-landing operations are predominantly covert in nature and sequenced as close or coordinated with the assault to minimise the resource and logistic burden and maintain the advantage of surprise.
Operational choices
Vessels operating on the surface are vulnerable and can disclose favoured channels or operating areas. Crewed Mine Countermeasures Vessels (MCMVs) require additional tailored defensive support if operating within enemy engagement range. Even uncrewed surface assets can be targeted by coastal defence missile and artillery systems which must be neutralised before assets are committed close to land. As swarm attacks by surface and air drones become more accurate and lethal, it is conceivable that surface assets will only be used once the landing force has committed to its area of operations and even then, at increased risk of destruction by enemy action.
So how does a pre-deployed LSG prepare itself for an assault when it is already in or close to its operating area? If stores and vehicles need to be reorganised from efficient and safe storage to assault order, the amphibious force will need to leave the littoral zone at the very time that it is looking to increase situational awareness. Meanwhile any advance force, pre-landing or MCM activity must operate without the need for additional defensive capabilities and without advertising the amphibious operating area geometry. The use of surface assets for low-risk deception only is a soft option that negates the need for adequate organic protection capability within the LSG design. The deduction is simple, mitigate for a denied or contested surface environment by augmenting sub-surface capabilities: the underwater domain is more covert and, for the time being at least, more survivable.
Technical options
Uncrewed, autonomous systems could be left behind to continue intelligence, surveillance, and reconnaissance (ISR) and MCM “tasking, and potentially as the senor-decider-effector chain is established they could contribute to area denial, pending the return of the amphibious force.
These assets could be mobile – either crawling or swimming before settling again to conserve power, to keep pace with the changing requirements of the littoral strike group and frustrate counter measures by the enemy. As the LSG achieves its objective and moves closer to sustain itself for as long as required, these assets could provide the seaward sensor/defensive screen or move with the task group to maintain a positioning network independent from GPS.
The sense-decide-effect system of system of systems will rely on a robust secure underwater communication network. In our vision exploiting the technology carried by each of the previously mentioned self-propelled nodes and vehicles.
Proven Capabilities
Our technology partners have over 50 years’ experience in the offshore energy sectors. Integration and testing in the amphibious context is the next step. Integration of acoustic array technology could maintain the force’s level of situational awareness. This technology is well understood and used extensively in the energy sector. Pre-positioned and pre-surveyed transponders can already provide centimetre accurate positioning independent of GNSS input. Sensor agnostic seabed nodes are already available, integration with acoustic, seismic, magnetic sensors is low risk and achievable within a very short time frame. Acoustic and optical communications options can support data transfers at speeds up to 1Gb/s depending on range.

Forcys is ready to help you now. Early engagement is needed to help solve the challenges the future operating space presents. We can use indicative blocks of proven technology to show you how our technology can help.
If you’d like to hear more about our vision of amphibious warfare in the future or think we could deliver some of these capabilities in partnership, contact us for more information.
Justin Hains MBE left the Royal Navy in 2020. Among other professional qualifications, he completed the Advanced Mine Warfare Course and the Amphibious Operations Planning Course during a career as a Mine Warfare Clearance Diving Officer and Principal Warfare Officer (Underwater).
The ViperFish is an all-in-one compact remotely operated towed vehicle (ROTV) ideally suited for expeditionary mine countermeasures (MCM) and explosive ordnance disposal (EOD) surveys. Martin Kristensen, VP of Hardware Development at our technology partner EIVA, explains all in this edition of The Watch.
“The ViperFish is a new surveying platform that we developed to address the growing demand for unexploded ordnance (UXO) surveying in the offshore wind industry,” said Kristensen. “It is a versatile and easy-to-use system that can be deployed from a vessel of opportunity. Expeditionary MCM survey requirements are very similar so navies can benefit from all our commercial experience to make their surveys far more efficient.”
Experience where it counts
“We wanted to incorporate all the lessons we learned from building and operating the ScanFish ROTV, the industry’s leading UXO survey platform, into the design of the ViperFish, creating a UXO surveying platform optimised to meet the demands of our customers. These include increasingly efficient surveys and where possible these needed to be automated. To support an increasing volume of surveys, new ROTVs needed to be compact, easy to launch and recover from a variety of vessels, including uncrewed surface vessels (USVs), and equipped with class-leading payloads and navigation sensors.
The system is built using the same building blocks as the ScanFish, enabling us to leverage all that experience. The first obvious difference between the ViperFish and the ScanFish is the shape. The ViperFish is cylindrical with actuated fins, while the ScanFish is shaped like an airfoil. The new system is as manoeuvrable, but the difference in shape offers a number of benefits:
- A lower drag coefficient: this means that it requires less power to tow. This is important for autonomous UXO surveys, as it allows the ViperFish to be deployed from smaller vessels or even from shore.
- More stability in rough seas: the pitch and roll are controlled by the actuators maintaining a more stable platform enabling you to work closer to the seafloor and maintain a stable platform at the sweet spot for the sensors providing improved data and therefore better decision making.
- A narrower profile enabling operations from smaller vessels: making it easier to transport and deploy. This is a major advantage for expeditionary surveys, as it allows the ViperFish to be deployed and recovered more quickly and easily.
It’s not just the platform. It’s the whole system. We conducted significant research to minimise the cable drag. By doing this, we can operate with smaller winches and deploy from a smaller surface area. We offer two shipment options: a self-contained cradle-box that can be shipped everywhere, or a container ready to integrate into a vessel.
It’s taken some time, but one of the most memorable things about the ViperFish is the first time we put it in the water,” said Kristensen. “On our first prototype test, we were out sailing 3 days and we had 100% uptime on the system. It was really a relief and a joy to see that all of our hard work had paid off.”

All the payloads
The ViperFish is equipped with all the sensors typically required on an ROTV, including:
- Solstice multi-aperture sonar: Used to create a two-dimensional image of the seabed. This image can be used to detect mine-like objects. The ViperFish uses the Solstice from our technology partner Wavefront Systems. This sonar is known for its high resolution and low power consumption.
- R2Sonic 2020 multibeam echosounder: It creates a three-dimensional image of the seabed. This is used to fill the gap ensuring 100 % coverage from a single survey line.
- OFG Hypermag: This magnetometer detects magnetic anomalies in the water or on the seabed generated by mines or other metallic objects while filtering out magnetic anomalies generated by the ViperFish itself.
- SPRINT-Nav Mini hybrid DVL-INS: Used to track orientation, position and speed; this system is from our technology partner Sonardyne. This information is used to create accurate maps of the survey area.
- Mini-Ranger 2 USBL positioning: The ultra-short baseline positioning system is used to track the ViperFish’s position in absolute coordinates. The Mini-Ranger 2 is a class-leading positioning system from our technology partner Sonardyne.
- Valeport sound velocity sensor: the sensor is used to optimise the sonar survey in real time, which is especially important when operating close inshore and within estuaries where sonar conditions can change rapidly.
The integration of these sensors into the ViperFish ROTV makes it a versatile and efficient UXO surveying platform. The ViperFish can be used to conduct surveys in a variety of conditions, and it can detect a wide range of objects.
Low-logistics, simple to operate, quick to train
“The ViperFish is operated by a crew of two people. The survey plans are prepared beforehand using NaviSuite Kuda software from EIVA. When launching the system, one person is responsible for supervising the ViperFish, while the other person controls the crane. At a speed through water of 2 to 10 knots, once in the water the ViperFish automatic controls take over, quickly swimming to the appropriate height from the seafloor within less than a minute. When the system is deployed one person is responsible for monitoring the automated mission while operating the ViperFish’s sensors and collecting data. If the ViperFish detects a possible UXO, the crew can mark the location on a map. The crew can then return to the location at a later time to investigate further. The system follows the seabed at a fixed height and can cope with slopes of up to 45 degrees. Plus it can replan its mission if obstacles are detected and avoid them in a safe manner while still obtaining high-quality data. When the mission is completed, the ViperFish is recovered by the two-person crew. We are also in discussions with USV manufacturers to make the launch and recovery totally automated.”
“The system is relatively easy to operate, even for people who are not trained hydrographers. The whole training process can be completed in a couple of weeks, it is mostly focused on learning how to set up the system and how to operate the sensors. If the crew is already experienced with using autonomous underwater vehicle (AUV) systems or the ScanFish, the training process will be a couple of days at most. Since the user interface of NaviSuite Kuda, EIVA’s survey software, is used widely in the commercial sector, there is already a large pool of contractors and trainers ready to support operations. In addition, sailors will be gaining valuable skills to support their transition to the commercial sector.”
Actionable data
“Ultimately, it’s about delivering our customers the best data, and you’ll be surprised how challenging it is to get these many payloads into the right form factor. But it has been worth it. We offer an incredible amount of area coverage rate of actual actionable data using class leading sensors.”
Please contact us to find out more.