Chapter 6: Maritime autonomous vehicles
233.The 21st century has seen the rapid development of autonomous technologies in many sectors, including the maritime sector. Witnesses noted that while maritime autonomous systems have been in use for some time, in particular for scientific research,314 a new challenge is presented by the emergence of maritime autonomous vehicles (MAVs). These replicate many of the functions of traditional vessels, and provide new capabilities for operators.315
234.Much of the development of such technologies has been for military purposes, with the US Navy and Royal Navy leading internationally.316 Professor Klein and colleagues highlighted several examples of autonomous vehicles already in development or use by the military, including “small vessel swarms”, “Seahunter” (a type of uncrewed surface vehicle developed by the US Defense Advanced Research Projects Agency) and “autonomous missile arsenal vessels”.317
235.UNCLOS was drafted at a time when maritime vehicles required a physical crew in order to operate. Many of UNCLOS’s provisions refer to, and place obligations on, the crew of the vessel. For example, Article 94 of UNCLOS requires all ships to be “in the charge of a master and officers who possess appropriate qualifications”. But maritime autonomous vehicles (MAVs) do not need a physical crew in order to operate, and some do not even need a remote crew. Commander Caroline Tuckett, Lead Legal Adviser in International Law at the Royal Navy, explained that vehicles can be classified by four ‘degrees’ of autonomy, as set out by the IMO:
“Degree 1 is a ship that has some automated systems but still has people on board … Degree 2 is a capability that can be operated remotely but still has seafarers on board. That could be for safety reasons, for maintenance or for any other reason. Degree 3 is where you operate a vessel remotely but there is nobody on board … Degree 4 is fully autonomous, which means that a ship is capable of making its own decisions.”318
236.MAVs raise classification issues. It is uncertain whether MAVs can be classified as ‘vessels’ (a term used interchangeably with ‘ship’), a warship, or whether they are simply devices or equipment. This is important as many of the rights provided for in UNCLOS, such as the right of innocent passage through territorial seas, apply to ‘ships’. Dr van Logchem also noted that if MAVs are classified as ships, then flag states will be under “numerous obligations”.319
237.Witnesses were clear that there is an urgent need for new regulation and guidelines to answer these questions, as “the technology is [currently] moving faster than international law”.320 Dr Galani told us that the IMO has undertaken a scoping exercise on the use of MAVs, and found that many of its conventions will need to be updated to “plug the gaps that exist”.321 Cdr Tuckett explained that the IMO is intending to produce a “code” that will plug these gaps and provide specific guidance. However, this will likely not be published until 2028.322
238.In the meantime, it is likely that the interpretation of the existing rules by those states already using MAVs, including the UK, will contribute to the establishment of customary international law about their use.
Military use
239.There are many potential applications of MAVs for military purposes. A key benefit of MAVs is that they can be used in situations where crew might be at risk, such as during conflicts or mine clearing. Cdr Tuckett provided examples of vessels the Royal Navy is currently testing for use in reconnaissance, surveying inland ports and harbours, and for identifying and classifying mines on the seafloor.323
The Royal Navy’s legal approach
240.Cdr Tuckett told us that MAVs are “not the first time … that new technology has developed and we have had to make sure that it is in accordance with international law”.324 Professor Evans agreed, telling us that “the law of the sea has always changed quite dramatically in the light of changing ideas of technology” and that there is “absolutely nothing new about our approach to legal regulation changing as technology changes.”325
241.In the absence of international agreements and regulation on the use of MAVs, Cdr Tuckett said that the Royal Navy is interpreting the provisions of UNCLOS through the lens of Article 31 of the Vienna Convention on the Law of Treaties. This states that: “A treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose.”326 She explained that while UNCLOS does not include specifics on how to regulate MAVs, “the principle of UNCLOS … is to provide for freedom of navigation and to demonstrate accountability for vessels operating under the principle of the freedom of navigation”, and that those “principles do not change because the technology has changed”. Therefore, under the Vienna Convention: “We just have to make sure that we apply those principles to our new technology”.327
242.In practice, Cdr Tuckett said that this has meant adopting a “principle of equivalence” when applying provisions of UNCLOS and related treaties when those provisions assume a vessel is crewed. For example, Rule 5 of the Convention on the International Regulations for Preventing Collisions at Sea says that “a vessel on the high seas must keep a good lookout ‘at all times’, using ‘sight and hearing’ and ‘by all available means’ in the circumstances”. She explained that using the principle of equivalence, the Royal Navy have ensured that “the software used to drive the vessels … has an ability that is as good as having a human watchkeeper on the bridge.” She noted that “in the absence of definitive regulation we feel that it is the safest way to proceed.”328
243.When asked whether other states agree with the UK’s approach, Cdr Tuckett said that other navies she has dealt with “broadly … agree”, but that “most navies are not developing this technology as fast as we are”, apart from the US.329
244.The Royal Navy is currently adopting a “principle of equivalence” approach to determine how maritime autonomous vehicles can fit into the existing legal regime. In the absence of international agreement, and as one of the leaders in the development of this technology, this seems a sensible approach and the Royal Navy should be commended for its careful consideration of these issues. The Government should monitor other state’s responses to the Royal Navy’s treatment of its maritime autonomous vehicles, and work with partner states to ensure the changes under discussion at the IMO reflect the sensible approach adopted by the Royal Navy.
Warship status
245.We heard that an important question for the use of MAVs in the military is whether they can be classified as ‘warships’. The Ministry of Defence explained that: “Under the Law of Naval Warfare only warships may lawfully use offensive force during armed conflict.”330 These are referred to as ‘belligerent rights’, and they include “kinetic strike, visit board search and seizure, laying mines, amphibious operations against enemy held coast, [and] blockade enforcement.”331 Warships are also granted ‘sovereign immunity’ in UNCLOS, meaning other states are prevented from exercising jurisdiction over them.
246.Warships are defined in Article 29 of UNCLOS as:
“A ship belonging to the armed forces of a State bearing the external marks distinguishing such ships of its nationality, under the command of an officer duly commissioned by the government of the State and whose name appears in the appropriate service list or its equivalent, and manned by a crew which is under regular armed forces discipline.”332
It is uncertain if a MAV can be considered a warship as it does not have an officer or a crew.
247.The Ministry of Defence told us that at present, MAVs being trialled by the Royal Navy are being registered as “government vessels on non-commercial service”. Vessels categorised in this way are not afforded belligerent rights, but they do have sovereign immunity, and other rights afforded to ships such as the right to innocent passage. Cdr Tuckett told us that to date there have been 23 vessels with “a form of autonomous capability” registered as such.333
248.Both Cdr Tuckett and the Ministry of Defence said that classifying MAVs as either warships or government vessels on non-commercial service ensures that there is accountability for their use.334 The Ministry of Defence explained that Article 29 of UNCLOS “confirm[s] state responsibility for the actions of warships and requires that the state have an accountable system of discipline to control the actions of those who operate them”, and incorporating autonomous vehicles into this regime will help to “regulate their proper use”.335
249.Whether maritime autonomous vehicles can be classified as warships or not will have significant implications for their use, including their protection from seizure by other states. In the absence of international regulation, the Royal Navy’s practice has been to register vessels in such a way to emphasise they are state owned and operated, providing them with sovereign immunity while ensuring the state can be held accountable for their actions. As other states begin to develop and use maritime autonomous vehicles, it will be important for the UK to work with like-minded partners to regulate these technologies with reference to these principles. Once again, the Royal Navy’s practical approach to ensuring equivalency with the provisions of UNCLOS is sensible and to be commended.
Cybersecurity considerations
250.We asked witnesses whether cybersecurity was a concern for MAVs. Cdr Tuckett explained that the software used on MAVs developed by the Royal Navy goes through “rigorous testing” and that “it takes a long time to get a vessel certified to the point where we will even let it go into remote-control mode, let alone off on Uniteits own.” She gave the example of the MADFOX vessel, which underwent more than a year of testing before it was allowed to be used in ‘degree three’ autonomy (remote controlled with people ashore).336
251.For civilian or commercial uses of MAVs, Dr Alexandros Ntovas, Reader in Maritime Law and Director of the Institute of Maritime Law at the University of Southampton, highlighted that the IMO has produced guidelines on maritime cyber risk management.337
Criminal use
252.Dr Galani told us that “criminals are much faster than states in adopting and employing technology”.338 Professor Klein and colleagues told us that there have already been several incidents where MAVs have been used for criminal purposes, such as the use of unmanned boat bombs by Houthi militants in the conflict in Yemen, or their use in the transport of illicit goods.339 This presents a maritime security threat.
253.We heard that UNCLOS provides a “starting point for establishing State rights and duties in responding to illicit activity at sea”.340 Professor Klein and colleagues explained that “the coastal State may exercise criminal jurisdiction over its territorial sea” and within the contiguous zone, “the coastal state has authority to prevent and punish infringements of its customs laws and regulations,341 which would typically include smuggling offences.”342 Other treaties, such as the UN Convention against Transnational Organised Crime (UNTOC) and the 1988 United Nations Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances outline additional responsibilities and rights of states.
254.But these rely on the ability of states to establish culpability where criminal acts occur. This is challenging when criminals use MAVs because, as Professor Klein and colleagues noted, “the level of autonomy and hence the level of human involvement has implications for characterising the vessel, as well as for determining liability for conduct at sea, including ascertaining which actor is liable.”343 States will therefore need to consider carefully how to account for the ways in which MAVs could be used for criminal activities when implementing international obligations into domestic law.344
255.In terms of how criminal use of MAVs will be handled from a military or law enforcement perspective, Cdr Tuckett envisaged two potential challenges: of accountability and intent.345 On the former, she explained that “jurisdiction is a challenge” because it may not be clear who owns a MAV—”it might be registered to a flag state registry in one country but remotely operated from another”. On the latter, she explained that the current Royal Navy procedures when attempting to determine intent rely on “hailing the master and hoping that someone on the bridge will pick up the radio”. She said that there are currently not clear answers on these issues as “the technology is still developing”, but the Royal Navy is “looking at it very closely and it is something that we will have to develop as time goes on”.346
256.Criminals are already making use of maritime autonomous vehicles, and in the absence of updated and specific regulation on their use, it is difficult to determine culpability for such acts. The principle of equivalency is a good starting point but there will be circumstances which warrant new regulation. As well as developing international regulations, states will need to ensure the use of maritime autonomous vehicles for criminal purposes is included in domestic legislation. We ask that the Government provide us with information in its response to this report on whether maritime autonomous vehicles have been used for criminal activities in British waters to date, and whether domestic legislation has proved adequate to tackle such breaches.
Commercial use
257.We heard limited evidence on the use of MAVs for non-military purposes. Dr Galani told us that “shipping companies keep investing in autonomous vessels for commercial purposes”. However, they face similar issues to those used for military purposes: UNCLOS and related treaties assume an on-board crew. She gave the examples of the SOLAS and MARPOL conventions, which have “provisions that explicitly refer to the fact that on board the vessel there is a master and there is a qualified crew” and “provisions that refer to cabins or other areas used by the crew”.347
258.The limited evidence we heard on MAVs for commercial purposes indicates that considerations for its use are at an earlier stage than for military purposes.
The role of the UK
259.As a leading developer and user of maritime autonomous technologies, the UK can play an important role in the development of customary international law through its own practice, both for military and non-military purposes. This will be supported if the UK develops domestic legislation on their use.
260.The Minister told us that the Department for Transport is leading on domestic regulation of maritime autonomous vehicles, in consultation with the Ministry of Defence and FCDO.348 Between September and November 2021, the Department for Transport held a “Future of transport regulatory review” consultation, focussing on maritime autonomy and remote operation.349 The review sought “views on areas of maritime autonomy regulation that are outdated, a barrier to innovation or not designed with new technologies and business models in mind”.350 Cdr Tuckett said that one of the questions asked whether people operating autonomous vehicles from shore should be classified as ‘crew’ and given “seafarer rights in the way the crew of a crewed ship would have”.351 Such a classification would have important human rights implications.352
261.We understood that the Government’s ambition is for relevant legislation to be ready in advance of the IMO’s code. Cdr Tuckett explained that the legislation would encompass civilian shipping, and that that it was her “expectation … that Royal Navy vessels and our government vessels will be exempt … in the way we are exempt from the Merchant Shipping Act”. However, she explained that this would not prevent the Royal Navy from “trying to follow those provisions wherever we could” and it will “provide a very helpful statement of intent from the Government as to how they wish to regulate uncrewed capabilities, which in turn will assist us in the Royal Navy.”353
262.The UK can also help develop law through engagement with the IMO’s proposed code to regulate the use of MAVs. On its website, the IMO says a core issue that needs addressing is the development of terminology and definitions, including clarification of the meaning of the term “master”, “crew” or “responsible person”, particularly for degrees three and four of autonomy. 354
263.The Minister told us that the UK has “committed to working very closely with the IMO and with IMO member states as this develops”, but as yet he did not feel “equipped to tell you how advanced that thinking is yet or how clear we are in the UK about our position on what those regulations ought to look like.”355 Andrew Murdoch told us that “In advance of 2028 … the discussion will be guided by the guidance that has been issued [by the IMO] and by state practice along the way.”356
264.The UK is a leader in the use of maritime autonomous vehicles and is in a position to set a strong international example. Domestic legislation and state practice, including through the Royal Navy, will be important for establishing customary rules about the use of MAVs. These will be important for guiding the work of the IMO on maritime autonomous vehicles. We ask that the Government updates us in its response to this report on the outcome of its ‘Future of transport regulatory review’ and provides a timeline for the development of domestic legislation.
265.In order to contribute effectively to the IMO’s new code for maritime autonomous vehicles, it is important that the UK Government comes to clear positions on issues including how terms such as ‘crew’ and ‘master’ can be applied to autonomous maritime vehicles. The Royal Navy’s practice provides a sensible example of how this can be done.
266.We urge the Government to be vigilant to cybersecurity issues relating to maritime autonomous vehicles which might cause serious operational and accountability issues.
315 Written evidence from Professor Natalie Klein, Professor Douglas Guilfoyle, Professor Saiful Karim and Professor Rob McLaughlin (UNC0003)
317 Written evidence from Professor Natalie Klein, Professor Douglas Guilfoyle, Professor Saiful Karim and Professor Rob McLaughlin (UNC0003)
326 United Nations Vienna Convention on the Law of Treaties Article 10: https://legal.un.org/ilc/texts/instruments/english/conventions/1_1_1969.pdf [accessed 7 February 2022],
331 Ibid.
332 Written evidence from Professor Natalie Klein, Professor Douglas Guilfoyle, Professor Saiful Karim and Professor Rob McLaughlin (UNC0003); UNCLOS Article 29
334 Ibid.
339 Written evidence from Professor Natalie Klein, Professor Douglas Guilfoyle, Professor Saiful Karim and Professor Rob McLaughlin (UNC0003)
340 Ibid.
342 Written evidence from Professor Natalie Klein, Professor Douglas Guilfoyle, Professor Saiful Karim and Professor Rob McLaughlin (UNC0003)
343 Ibid.
346 Ibid.
349 Department for Transport, ‘Future of transport regulatory review: maritime autonomy and remote operations’ (28 September 2021): https://www.gov.uk/government/consultations/future-of-transport-regulatory-review-maritime-autonomy-and-remote-operations [accessed & February 2022]
350 Ibid.
352 Ibid.
354 International Maritime Organization, ‘Autonomous shipping’: https://www.imo.org/en/MediaCentre/HotTopics/Pages/Autonomous-shipping.aspx [accessed 7 February 2022]