Table of Contents
Introduction
In 2018, an aerial drone the size of a pigeon shut down London Gatwick Airport for 33 hours. Over 1,000 flights were cancelled, and 140,000 passengers were stranded at the terminal gates. It cost the airlines more than £47 million ($US64 million).
It brought airport security, the Civil Aviation Authority (CAA), and the UK Anti-Terrorism network to their knees, and Gatwick’s runway fell silent for over two days. The operator is still at-large.
Even before this, people were suspicious of drones. This incident proved that they can cause chaos in the wrong hands. If a simple consumer drone could cause this sort of disruption, what could a criminal or hostile state do with more sophisticated devices?
Despite these concerns, the maritime industry is embracing aerial drone technology to make progress in exciting directions.
From conducting oil rig leg inspections in the North Sea, to ‘breathalysing’ whales to determine pod health, we’ll take a deep dive and unpack the exciting and surprising world of maritime aerial drones.
What are drones?
What is and isn’t a drone is the subject of energetic debate in certain circles. According to the Oxford English Dictionary, a drone is “an aircraft without a pilot, controlled from the ground.” That’s a fine starting point, but nowadays we use “drone” to describe unmanned boats and submarines too. Some drones are even autonomous, rather than just “controlled from the ground.”
In the maritime industry, we’re fairly pragmatic: we skip the arguments about definitions, and just use all three types of drone (flying, floating and swimming), in both their autonomous and remote-controlled forms.
This report focuses on aerial drones, also known as “Unmanned Aerial Vehicles” (UAVs).
You’d be forgiven for thinking that there’s no difference between aerial drones and remote-controlled planes. They often overlap and they usually fall under the same regulations, but drones are distinct in several ways.
Compared to remote-control planes, drones:
- are more stable and substantial;
- can carry heavier loads;
- are more manoeuvrable; and
- have a longer range.
In addition, many aerial drones can operate autonomously or have some autonomous functions. This flexibility makes them ideal for maritime operations.
You’re probably already familiar with the most popular type of aerial drone: the quadcopter. Quadcopters are helicopter-like drones with four sets of rotors, but they’re not the only aerial drones out there. There are an astonishing range of aerial drones available, from single and multi-rotor drones to fixed-wing drones, and even drones that look like birds or float in water to recharge.
Supporting technologies
Aerial drones themselves are completely useless (although fun to play with): it’s their payload that matters. They’re just a platform for the wide range of technology that makes them uniquely useful. Here are a few of the common and promising upcoming technologies you’ll find in most aerial drones today:
Stabilisation
Gyroscopes were all the rage among 1980’s schoolchildren. Wind a piece of string around it, start it spinning, then balance it on the end of a pencil. When you pushed it off-axis, it came back to the same angle. If you had grasped it and tried to change the angle, you’d feel it resist the change. They drove the teachers just as crazy as today’s fads, but they demonstrated perfectly how gyros work.
Rotor-type drones are inherently unstable. Without some way to prevent it, they would roll over or wobble around in flight. A combination of careful design, gyro-stabilisation, and automated flight control systems prevent this.
The gyroscope in a drone is part of the inertial measurement unit (IMU), which detects acceleration and changes in pitch, roll and yaw. The IMU feeds information on these small changes to the flight control system, which corrects for them without the operator noticing.
You’ll find aerial drones with three-axis or six-axis stabilisation. This is misleading—there are only three axes:
- roll (what a ship does in a beam sea);
- pitch (what a ship does in a head sea); and
- yaw (what a ship does with a trainee at the wheel).
Six-axis stabilisation describes a system which combines a three-axis gyro with a three-axis accelerometer or 3D compass. Modern accelerometers usually use Micro Electronic-Mechanical Systems (MEMS). MEMS chips measure tiny changes in electrical signals when microscopic structures on a chip move around in response to gravity. This means they can detect the same things as the gyro, but in a different way. Combining gyro and accelerometer data gives the drone’s systems more information to work with.
Drones with six-axis stabilisation are easier to fly and more manoeuvrable than those with three-axis stabilisation. If your use-case relies on a stable platform, six-axis stabilisation is essential.
Sensing
Sensing and detecting what’s around them is one of the main uses for aerial drones, both for the drones’ survival (not crashing into things) and to perform their intended function. As you’ll see later, drones are often used for detecting and recording anything from ballast tank inspections and gas levels; to tracking sharks and finding survivors in the water.
With the rise of consumer drones, recording visual data—photos and videos—requires no explanation. If you have a drone at home, it probably records photos and videos in the same way as your smartphone. As well as the obvious uses, we can use visual data in photogrammetry—a method of generating accurate 3D models. Cameras that detect other wavelengths such as infra-red and UV are just as versatile.
Most drones have range sensors for object detection, either to avoid crashing, or to hover at a set height, but range sensors offer so much more.
Sonar (sound navigation and ranging), radar (radio detection and ranging), and, more recently, lidar (light detection and ranging), are forms of range sensing that can—and have—filled books. At a conceptual level, they all work the same way: emitting a pulse that travels at a known speed, and timing how long it takes to bounce off something and return. The sensor knows the speed of the pulse, so it can calculate how far it travelled. As it also knows the direction it transmitted the pulse, it can vector the target’s location. By combining information from multiple pulses or measuring the Doppler shift of the reflected pulse, it can calculate movement or build a map of the area.
As the names suggest, sonar uses sound pulses, while radar uses radio waves, lidar uses light, and a laser range finder (LRF) uses a laser. Each has pros and cons, mostly relating to power consumption, usable range, and the types of interferences that affect it.
Despite having a similar name to other range-finding and detection technologies, ViDAR (visual detection and ranging) works completely differently. You may remember stereoscopic viewers or the early red/blue 3D glasses that showed a slightly different image to each eye, creating the illusion of depth. ViDAR works on the same principle. It uses multiple fixed high-resolution cameras to scan the surface of the ocean and compares the images to locate objects. ViDAR can detect a person in the water from at least 1.7 nautical miles away, making it ideal for deployment on search and rescue (SAR) drones and in various security applications.
Whether in confined spaces or out at sea, aerial drones are ideal for environmental sensing and sampling. Temperature, pressure, humidity, and magnetic field sensors can provide key meteorological and climate data, while gas detectors and chemical sensors provide safety-critical information for activities like tank entry or SAR operations.
Control and communication
Most aerial drones have a remote control system, and can transmit data to the operator or a base station. They communicate via radio-frequency (RF) transmission on 2.4 to 5.8 GHz. Like any radio signal, the range varies with atmospheric conditions, weather and other propagation variables. While most can easily out-fly the controller’s range, that’s rarely the goal. More recently, 4G LTE (or Long-Term Evolution) and 5G drones have extended the practical operating range.
For effective data transmission, drones must balance range with data rate. A higher-frequency signal allows faster data transfer, but over a shorter range. While this is no problem for a hold inspection on a ship, it could pose issues for long-range SAR or anti-piracy operations.
Advantages of aerial drones in maritime applications
Computers are better than humans at tasks like data collection and quantitative analysis. Drones can collect the data more efficiently and with less proclivity to error than we can, all whilst keeping us from danger. Given that, it’s no surprise that the industry is turning to technology to carry out dull, dirty and dangerous tasks.
Working aloft and in tanks or confined spaces remains a common cause of injury and death among maritime workers, and humans are often ill-suited to tasks like long-range surveillance and search and rescue (SAR). A moment of distraction, and someone is injured or killed. A wave passes at the wrong moment, and a would-be rescuer misses the survivor in the water. By taking on these jobs, technology—including drones—can save lives.
Aerial drones are easy to use, and they provide a powerful and versatile multi-role platform. They keep people away from danger; are often far more cost-effective, and environmentally-friendly than other methods; and require operators to undertake less training than a conventional aircraft pilot requires.
Maritime challenges for aerial drones
As with every technology, while aerial drones can fix some problems, they pose problems of their own.
As we have seen, maritime aerial drones are heavily reliant on sensing, electronic positioning, and navigation aids – principal of which is GPS.
The now ubiquitous global positioning systems (GPS) need little explanation here. GPS works by measuring the range between the GPS receiver and at least three or four satellites. Because the receiver knows the satellites’ positions, it can use triangulation to calculate its own position. GPS has been indisputably transformational in ocean navigation.
The advantages of GPS to pre-plan flight paths and accurately identify a drone’s position is obvious. Less obvious is the problem that GPS reliance poses for ship-based aerial drones. Many drones have a “return-to-base” function—when their battery is low or they lose connection with their controller, they return to a pre-set GPS position. This usually defaults to the position they took off from in terrestrial operations. Unfortunately for the drone: ships move. Therefore, employing this method on a moving vessel means that by the time the drone returns to the geostatic position, there may be nothing but water to return to.
Acknowledging this issue, some manufacturers offer a modified return-to-base logic. For shipboard operations, drones that employ a ‘dynamic’ homing capability that allows the aircraft to return to the remote control, rather than the take-off location, are recommended.
In a similar vein, some drones find it difficult, if not impossible, to calibrate their positioning and IMU sensors without a geo-stationary launch platform. This can prove to be a considerable issue on board smaller vessels, or those subjected to inclement sea states. In some cases, calibration can be conducted ashore before departure. Where this is impractical, specialist aircraft should be employed.
Common to most flight environments, there are bureaucratic rules concerning the use of drones for maritime applications. In most countries, aerial drones fall under civil aviation rules. These rules may restrict where and how high you can fly, limit the size of the drone, and impose registration fees, training requirements, and fines for non-compliance. The rules vary by country, but common-sense is a good starting point: avoid flying drones near airports or military facilities, and look up the specific rules for your country or region before investing in a drone. In most countries, few or no regulations apply to drones used indoors. This makes drones an adaptable solution for internal inspections.
Practical concerns
The earth is two-thirds water. Ships are generally made of steel. For the maritime industry, these two factors alone pose several practical challenges for aerial drones.
We’ll start with the ships.
Steel can block or weaken most radio signals. As most drones rely on radio signals to communicate, this restricts their use. While drones can and are being used inside steel tanks and cargo holds, this often stipulates that either they need to function autonomously, or that the controller needs to be inside the space with them (or at least at the entrance). As avoiding entry to dangerous spaces is one advantage of drones for inspection, this limits their use; however, increasing use of technologies like ScanReach’s wireless connectivity may overcome this problem.
The next problem is the ocean itself: if a drone crashes into the ocean, it’s very likely a total loss. Less obvious is the fact that the lithium ion batteries used in drones are sensitive to moisture. Even a small amount of moisture or increased humidity can reduce battery performance. As moisture and humidity are quite normal at sea, this means that a drones’ performance will be worse than similar drones ashore. Hence the concern about crashing when the battery runs out. But it gets worse.
When you travel with a commercial airline, you are asked if you have rechargeable batteries in your baggage. This is because, despite their advantages, lithium ion batteries pose a serious fire risk. For commercial drones to be viable, several spare batteries are required for each drone to maximise flying time. The more batteries carried, the higher the risk.
As well as moisture, drones are subject to the same weather factors as any other aircraft: in freezing conditions, poor visibility, rain, snow, hail, or strong winds, they may not be capable of operating safely. Even in non-freezing temperatures, propeller icing can damage the propellers or cause the drone to crash. To prevent this, many manufacturers specify weather operating limits for their drones. Unfortunately, some studies suggest that, for normal drones, sticking to these limits provides as little as two hours a day of flying time.
Besides the general practical and safety considerations, ship-specific restrictions are a factor. Particularly on tankers, drones must be intrinsically safe, or the space to be inspected must be fully ventilated or inerted. Because spinning plastic rotors and electric motors are not inherently intrinsically safe, at the time of writing there are no intrinsically safe aerial drones on the market; however, there are some in development, and Scout has successfully carried out tests and drone inspections in a flammable atmosphere with no problems.
Technical concerns
As with all recent technology, security and privacy both present problems.
On the security front, hacking, jamming and GPS spoofing are the main things to worry about.
As many consumer drones’ radio control signals aren’t encrypted, hackers can take control from up to a mile away. Once in control, they can land the drone somewhere and steal it, use it for their own purposes, or simply intercept the data that it’s transmitting.
Jamming is simpler, but potentially more destructive. Drones are susceptible to two forms of jamming:
- control and communication systems; and
- GPS.
As the name suggests, jamming “jams” the signal, so neither the operator nor the drone can receive it. It’s technically very easy to do, but it’s not targeted—it will disrupt all signals over a wide area. If a drone has a return-to-base system, it should return when it loses the signal, unless the GPS signal is jammed or spoofed as well.
GPS spoofing is more difficult to do effectively. Conceptually, it sends a fake GPS signal to a GPS receiver, making the receiver think it’s somewhere else. Criminals can use spoofing to redirect a drone along a different flight path; bypass its return-to-base function; or even use the drone to cause physical damage.
Anti-jamming and anti-spoofing solutions exist, but they’re normally too big to fit in small drones.
Safety, security and ethical concerns
Drones are powerful, flexible, and ideally suited for surveillance. On the ethical front, this raises obvious privacy concerns. While this is a less obvious concern in the maritime industry, it is something that should be considered.
Drone safety issues relate mainly to interactions with aircraft, the environment (both inside and outside), and other assets. While it should be obvious that flying near aircraft can be a problem, so can flying a non-intrinsically safe drone into the wrong area, dropping a payload, or colliding with a person. While aerial drones have a smaller environmental impact than alternatives, we must consider the use of limited resources like lithium for batteries, and the resultant pollution when drones are lost at sea.
Governments and NGOs use drones for legitimate surveillance, but there is nothing to stop criminals from doing the same. In our connected world, even video from a crew member’s drone can provide intelligence to potential attackers. While there are no reports of this in maritime, pirates have become increasingly sophisticated. It seems inevitable that criminals will use drones to locate, assess, threaten and attack maritime targets.
Current maritime uses for aerial drones
There are five categories of current uses:
- Small-scale surveys and inspections
- Large-scale surveys and inspections
- Emergency response
- Research
- Delivery and logistics
As you’d expect, there is some overlap between these categories.
Survey and inspection is the broadest category. Uses range from inspecting blades on a wind turbine to taking measurements across hundreds of miles of ocean.
1. Small-scale survey and inspection
Internal inspections
Despite years of training and forests of paperwork, tank entry is still a leading cause of work-related deaths at sea. Hold inspections, while killing fewer seafarers, are both tiring and tedious—inspecting one hold isn’t too bad, but staying focused for nine or eleven is a big ask. Even for an alert and motivated inspector, tanks and holds can be both huge, and a rabbit warren. It’s often physically impossible to complete a thorough close-up inspection without extensive scaffolding, an unreasonable amount of time, or both.
Tank and hold inspections will always be necessary. Aerial drone surveys can save time and money, reduce both the risk and the workload, and provide a clearer record and more detail than a human.
The concept is simple: fly a sensor-equipped drone around the space and record the flight, with close-ups of anything interesting. If necessary, a person can enter and inspect any areas of concern identified by the drone. Even if human inspection is necessary, it still reduces the time spent inside the space, and a gas-meter-equipped drone can considerably improve the safety of a tank entry.
Early drone inspections relied on a human to both fly the drone and monitor the video feed. More recently, Artificial Intelligence (AI) has paved the way for autonomous operation and automatic crack and anomaly detection, cutting the inspection time from days to hours.
DNV have produced an interesting video showcasing this capability aboard a drone manufactured and operated by a spin-out from the Norwegian University of Science and technology. Scout Drone Inspection’s Scout 137 is a tethered drone system for inspection of confined spaces and indoor assets. The lidar creates a 3D map of the space, and the system tags all images and video with position data. The tether system bypasses battery and communication problems, giving unlimited flight time and a supposedly reliable, high-bandwidth data link.
Another notable operator, who are approved by Lloyd’s Register, DNV and Class-NK, Drone Inspection Services specialise in detailed structural surveys. Using a Flyability Elias drone, they inspect ballast and cargo tanks, as well as jack-up rigs, reportedly saving clients up to $2 million.
With a collision-resistant cage, Flyability’s Elias inspection drones are impact, dust and splash-resistant, and (importantly for the maritime industry) mistake tolerant. They save all data to the SD card so it’s accessible with no special software, while easily swappable batteries let operators make several inspection flights without worrying about battery life.
External inspections and surveys
If you’ve ever stared up at a ship, offshore platform or wind turbine, you’ll understand why inspecting it is a daunting task. The sheer scale of the job means crews don’t inspect them as often or as thoroughly as might be ideal—it’s difficult, dangerous, tedious and time-consuming, which makes it expensive. Aerial drones can change that.
As defined by the International Association of Classification Societies (IACS), Classification Societies verify the strength, integrity and reliability of ship structures and systems by surveying vessels to confirm compliance with rules and standards. In practice, they spend a lot of time surveying ships and offshore installations. In 2019, IACS noted, “…[drones] offer greater efficiency, higher flexibility, and increased reliability in the day-to-day activities of survey and inspection without impairing the result of those surveys.”
The use of aerial drones for remote surveys has been growing, and several of the leading classification societies, including DNV, Lloyds Register, and ClassNK approve their use for class surveys. But it’s not only classification societies who want to inspect maritime structures.
Many offshore platforms produce natural gas as a by-product . If they can’t dispose of it in any other way, they flare it or burn it off at the top of a flare stack. These flares are critical—if they’re damaged or stop working, the gas either vents to the atmosphere or settles over the platform. Neither option is ideal, for obvious reasons, platforms want the flares as far as possible from their workers. This makes flare inspections expensive, dangerous, time-consuming, and ideal for aerial drones.
The same applies to offshore wind turbines, which are bigger than many people think. With moving parts exposed to the weather, regular inspection and maintenance is essential to keep them functioning. Aerial drones are an easy and cost-effective way to collect detailed images of their condition, which human experts or AI can analyse for signs of wear, damage, or deterioration. Drone-mounted thermographic cameras can detect delamination and separation of internal composite layers in the blade, allowing early intervention.
Draft surveys
Draft surveys are a common method of calculating the weight of a ship and cargo. The amount of water a ship needs to float (its draft) changes in proportion to the weight loaded or discharged, so checking the drafts before and after loading is an obvious way to calculate the quantity of cargo loaded or discharged.
While conceptually simple, reading drafts is a time-consuming exercise that usually involves either a small boat, rope ladders, or both. The difficulty of getting accurate draft readings means draft surveys are only carried out when unavoidable.
In 2020, a leading naval architecture and marine engineering company, Foreship, started using drones for draft surveying. After successful trials, they added drone draft surveys to their list of offerings. As amphibious drones become more popular, drone draft surveys are likely to proliferate further.
2. Large-scale survey and inspection
It’s no surprise: there’s a lot of water in the ocean, and it’s hard to keep track of what’s happening out there. From monitoring pirates to checking for oil spills, ships can only monitor relatively small areas. Whether keeping an eye out for refugees, or providing coastal security, aerial drones are cheaper and easier to operate than aircraft, and can cover a greater area than any ship ever could.
Not all drones are suitable for long-range inspection and surveillance. Such drones must be able to operate at longer ranges, have reliable communications, autonomous functions, and be able to survive a water landing.
Aeromao’s Talon is an example of an affordable fixed-wing aerial drone that is designed to land autonomously on the water. With a video-link range of up to 20 km and the ability to operate up to 30 km from base, in up to 40 km/h winds, it appears suited to coastal maritime surveillance and inspection.
Security
It’s not just private companies turning to drones: governments are too. Since 2017, the European Maritime Safety Agency (EMSA) has used drones to help with border control, pollution monitoring, migrant detection, and monitoring and detection of illegal activities such as poaching and drug trafficking.
Australia, responsible for 14% of the world’s oceans, also uses long-range aerial drones to monitor its coastline. The drones are deploployed for civilian problems, including illegal fishing, drug or people smuggling, and search and rescue operations; as well as the military problems of anti-surface and anti-submarine warfare.
Aerial drone fisheries monitoring is growing slowly, particularly in countries like Belize and the Seychelles, with limited resources and enormous areas to patrol.
Environment
Humans are becoming more aware of the impact our activities have on the environment and the terrible consequences of ignoring it, but the oceans are vast. For most of our history, we’ve relied on intermittent reports by ships, whistleblowers, and more recently satellite data to monitor the oceans. While programs like the voluntary observing ship scheme provide useful data, it’s restricted to the small area around a ship. While aerial drones have other limitations, they can help to fill the data void.
From monitoring oil spills and sulphur emissions, to tracking coral bleaching and counting whales, aerial drones can be far more efficient and cost-effective than the alternatives.
In the public consciousness, marine pollution and oil spills are synonymous. The emotional impact of seeing wildlife coated in thick oil is impossible to ignore, but oil spills—or even the discharge of oil at sea—remains difficult to monitor.
At sea level, detecting spills requires close proximity, and it’s hard to determine the extent of the affected area. Radar and satellites are also of limited use. Until recently, conventional aircraft were the most effective way to monitor and track oil spills at sea; now, aerial drones can help. EMSA uses Nordic Unmanned’s aerial drones to support oil pollution response. The drones’ footage helps on-scene coordinators assess the situation, deduce the extent of the spill, and allocate resources accordingly.
As for stack-emitted pollutants, most ships run on fuel oils which create sulphur oxides (SOx) and nitrogen oxides (NOx). These are known to pollute the atmosphere, leading to acid rain and ocean acidification among other negative effects for people and the planet. Aerial drones with sensors to detect and measure SOx, NOx, and CO₂ in ships’ exhaust emissions can identify non-compliant ships and inform officials at the next port. As ships know they’re monitored more closely in port, some ships switch to clean fuels in port making non-compliance hard to prove. At-sea emissions measurement may help to improve compliance.
Nordic Unmanned provides aerial drones for measuring maritime emissions and ensuring compliance with IMO regulations on air pollution from ships.
Wildlife needs more direct protection. Whales, the largest mammals on the planet, can live (undisturbed) for hundreds of years. Whales are only one of many species affected by human activity on the oceans. Even if we ignore whaling, offshore activities can change their behaviour, driving them away from feeding and breeding grounds—or even ashore. Scientists and those involved in offshore exploration want to monitor whales, but until recently, the only options were inefficient (satellites), or severely restricted (people with binoculars). Now, researchers and offshore companies can use specially equipped aerial drones to monitor their impact on marine wildlife and create responsible action plans, saving time, money, and wildlife populations..
A subsidiary of the Parrot Group, senseFly’s fixed-wing aerial drones simplify the collection and analysis of geospatial data across industries and regions. By assessing populations of marine animals, including seals, sharks and turtles, they can track the impact of operational changes. This crosses over with the research uses of drones.
3. Emergency prevention and response
There are two basic rules to seafaring:
- Keep the water out;
- Keep people and payload onboard.
Seafarers support one or both rules in everything they do. While humans may have evolved from water animals, we’re not designed to survive in the ocean unaided for long. In maritime emergencies, time and information are key—finding survivors quickly can be the difference between life and death. From helping distressed swimmers at the beach, to finding survivors after a man-overboard (MOB) or sinking, aerial drones can help.
The Little Ripper Lifesaver carried out the first recorded drone surf rescue in 2018, dropping a floatation aid that could support four people, and tracking the rescue. These are now in regular use in Australia, and not just for rescue purposes.
Both ashore and at sea, Australia’s infamous for its wildlife. Flying overhead, the Little Ripper automatically identifies and tracks sharks and crocodiles, warning swimmers with a loudspeaker if they get too close.
Search and Rescue (SAR)
Patrolling beaches is essential, but most seafarers spend their lives much further away from land. In September 2020, the UK Maritime and Coastguard Agency (MCA) trialled Elbit Systems‘ Hermes 900 aerial drones for SAR operations. Able to fly for 36 hours and equipped with SAR radar, automatic identification system (AIS), emergency position-indicating radio beacon (EPIRB) and satellite communications, as well as electro-optical/infra-red (EO/IR) cameras, the drone is ideal for SAR.
Human rights
Humans have rights at sea, just as we do ashore. Enforcing those rights ashore is a growing problem; enforcing them at sea is even harder. The Outlaw Ocean Project, which has spent years reporting on lawlessness at sea, describes the oceans as, ‘…the Last Untamed Frontier.’ The difficulty of monitoring the oceans can make it nearly impossible to gather evidence of rights violations.
In the Mediterranean, most human rights organisations rely on ships, volunteers with binoculars, and aircraft to monitor refugee safety, but a few take a different approach. Migrant Offshore Aid Station (MOAS) has used Schiebel Camcopter drones to patrol a sea area near Libya, saving over 8,800 lives in five months. Spanish NGO Open Arms is testing a specially equipped fixed-wing autonomous drone to locate vessels in distress and alert the rescue ship.
4. Research
Maritime research faces immense challenges. The size of the oceans and the difficulty and expense of even accessing and locating research areas present barriers to even the best-funded research. While aerial drones can’t eliminate these barriers, they go some way towards lowering them.
One of the most widespread uses is for counting, tracking and weighing a wide range of marine animals, from bluefin tuna sizes and whale breath testing, to box jellyfish and seabirds. Compared to alternatives, aerial drones have little measurable impact on the marine animals they’re observing.
Aerial platforms like drones are also ideal for studying temperature and water movement, such as surface currents, tidal streams, waves and swell. This isn’t just an academic question, as this information can help to identify potential sites for offshore wind farms, tidal generators, and other marine projects.
Many of the uses of aerial drones in maritime research crossover with the uses for surveillance and inspection discussed previously. This is especially true in environmental and climatology-related fields.
5. Delivery and logistics
On land, drones are delivering everything from your shopping and parcels to blood, insulin, and defibrillators. It’s only reasonable that the maritime industry joins in too. In March 2019, Wilhelmsen’s autonomous aerial drone delivered 1.5kg of essential supplies from shore to MV Pacific Centurion in Singapore, marking a first for the maritime industry. Faster, safer, and up to 90% cheaper than the usual method of delivering supplies by boat or helicopter, we can expect this to become more common in the near future as shipowners, governments, and ports recognise the benefits.
From container tracking to offshore deliveries, radio frequency ID (RFID) tagging is increasing across the maritime industry. For large warehouses or container yards, drone RFID relays may one day help to complete inventories or locate a particular cargo unit.
Future maritime uses for aerial drones
Lifesaving
In 2017, a DJI report found that, statistically, drones were already saving about one life a week in rescues across swamps, mountains, beaches and boats. At first, it was just private citizens using their drones to help, but as organisations saw the potential they designed dedicated rescue drones. As you’d expect, these are mostly land-oriented, but the maritime industry is catching up.
The Pars quadcopter drops life rings to swimmers in distress. At first glance, this is like Australia’s Little Ripper, but Pars launches from vessels or dedicated floating platforms. While still in development, this has potential for larger-scale rescue operations, or even simple man-overboard situations. In the future, there’s no reason it should be restricted to life rings—Zipline already uses drones to deliver blood, the Royal Navy is testing drones that can drop a life raft, and argodesign has proposed a drone ambulance that can transport a patient. A payload is a payload, so watch this space.
Arctic oil spills
At the more extreme end of the spectrum, as the ice melts and the Arctic opens up new navigable routes, aerial drones could play a part in cleaning up after oil spills. Cleaning up an oil spill is challenging even in populated, accessible regions; responding to an oil spill in the Arctic faces problems at every turn. In 2015, Jessica Garron and a team of researchers from the University of Alaska tested a novel solution for cleaning up Arctic oil spills: use an aerial drone to drop burning gelled gasoline on the spill and burn it off. Whether or not the air pollution from burning is better than that caused by transporting traditional cleanup equipment to the area, it’s an interesting approach to a challenging and serious problem.
Amphibious drones
The ‘Naviator’ looks like a normal quadcopter, but looks are misleading—part-submarine, part-aircraft, it swims as well as it flies. Able to operate in partial or full autonomous mode in the air, it has obvious potential in both research and small-scale inspection applications. From ballast tanks to hulls, coral reefs to harbours, and all sorts of maritime research, the advantages of a single inspection platform for both above and underwater are clear. As maritime aerial drone use expands, we’ll see more amphibious or multi-modal drones, if only to reduce the attrition rate when they crash.
Monitoring and evidence gathering
Just as coastal states increasingly use aerial drones to monitor and secure their coastlines against outside threats, so do human rights organisations ashore use aerial drones to gather evidence of human rights violations. In the future, we can expect to see human rights NGOs expand their use of drones for monitoring and evidence gathering.
Firefighting
Fire at sea is every seafarer’s nightmare. Fighting large fires is never easy; fighting them on a ship adds layers of complexity. With some container ships carrying up to 24,000 containers, even accessing an individual container is difficult. It’s easy to imagine firefighting drones like the Wild Hopper, MRRD or Walkera models one day being used to manage shipboard or port fires.
De-icing
People who’ve never been to sea might picture seafarers lounging around in the tropics. Unfortunately, life at sea rarely comes close to that image. Icing, or the formation of ice on ships, offshore platforms, wind turbines and other maritime assets, is a common problem in certain areas. As the Arctic routes open up, more ships will have to deal with icing.
Apart from being inconvenient, it’s dangerous. Too much weight high up can capsize a ship, or damage or decrease the efficiency of a wind turbine or offshore platform. Once it’s formed, removing ice traditionally involves lots of people with wooden hammers. A lucky few have a high-pressure steam rig to help, but climbing around in ice is risky.
De-icing drones can help. Aerones’ tethered drone can de-ice a wind turbine for 20% of the time and cost of rope access, and far less risk. Just imagine what it could do with an iced-up container stack.
3D Imaging
The time and expense of 3D imaging is one factor slowing adoption of extended reality (XR) and advanced simulation in maritime. Using drone footage, companies can use photogrammetry or videogrammetry to easily generate 3D models for training, maintenance planning, publicity and more.
Drone swarms
If a single aerial drone is useful, think what a swarm of interconnected autonomous drones could do. Researchers at Delft University of Technology have developed algorithms for ‘Sniffy Bug: A Fully Autonomous Swarm of Gas-Seeking Nano Quadcopters in Cluttered Environments.’ As the title alludes, these tiny aerial drones can locate a gas leak quickly and safely, allowing responders to focus on managing the leak rather than wasting time searching for it.
With the increasing use of gases as alternative marine fuels, this is a promising safety improvement for all vessels, not just for gas tankers and offshore installations.
Conclusion
In an industry full of dull, dirty, difficult and dangerous tasks and short-handed ships, aerial drones are here to help. In 2019, Baumler et al. confirmed what seafarers already knew: on many ships it’s impossible to complete the tasks required with the crew available in the time allowed. That leads to overwork, overwork leads to fatigue, and fatigue leads to accidents. The obvious solutions are to increase crewing levels, or to decrease the work load. That’s where assistive technologies like aerial drones come in.
Unlike many assistive technologies, which require large investment in equipment and training, even the cheapest consumer drones can reduce workloads and improve safety without threatening jobs. In many countries, drones are a familiar sight both for commercial and recreational use. When people seek solutions, it’s only natural to turn to the familiar first, so the widespread adoption of drones ashore almost guarantees their spread in the maritime industry.
In the coming years, rechargeable batteries, sensors, robotics, communication channels, AI, and big data will all improve, and aerial drones can take advantage of every development. For once, maybe the maritime industry will even lead the way.
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