Survey Report on International Deliberations
Regarding Legal Liability for Autonomous Ships (Fiscal Year 2025)

21 March 2026

Having completed the survey work regarding the above subject, we hereby submit our report as follows.

Part 1:  Criminal Justice Proceedings in the United Kingdom

1. Prosecuting Authorities for Maritime Offences

 (1) Prosecution by Bodies Other than the CPS (Crown Prosecution Service)

     In the UK[1], private prosecution has long been recognised under common law[2] .

 Legislatively, Section 6(1) of the Prosecution of Offences Act 1985 states that ‘nothing in this Part shall preclude any person from instituting any criminal proceedings’, confirming that no provision in this Part prevents any person from bringing criminal proceedings. In practice, numerous private prosecutions are brought[3] . Whilst private prosecutions are intended to complement those brought by the Crown Prosecution Service (CPS), they are costly and difficult for individuals to pursue[4] .

 This represents a significant difference from Japan, which adopts the principle of exclusive prosecution by public prosecutors[5] .

  (2) Prosecution by the MCA

Maritime and Coastguard Agency[6] (hereinafter ‘MCA’) is the statutory authority responsible for enforcing the Merchant Shipping Act 1995[7] (hereinafter ‘MSA 1995’) and associated legislation, and may bring criminal proceedings in appropriate cases. This is based on the fact that such powers are widely recognised as common law rights held by bodies other than CPS, and are expressly authorised under section 6(1) of the Prosecution of Offences Act 1985. In the UK, criminal prosecutions by bodies other than CPS are permitted as a matter of principle; consequently, there is no provision corresponding to Article 247 of Japan’s Code of Criminal Procedure.

 Furthermore, MCA’s power to prosecute is based on section 256(1) of the MSA 1995,[8] and on the interpretation that the enforcement powers conferred on the MCA under the Act include the power to initiate criminal proceedings (Section 58 of the Act stipulates that, in England and Wales, no prosecution may be brought without the consent of the Secretary of State or the Director of Public Prosecutions, thereby presupposing that the MCA has been granted prosecutorial powers); accordingly, MCA is generally understood to have prosecutorial powers under the law[9]. Accordingly, MCA Enforcement Policy Statement explicitly states that ‘prosecution is the most serious enforcement measure available to MCA’[10] .

2. Administrative Sanctions and the Decision Whether to Prosecute

　　 In the UK, there also exists a system similar to Japan’s suspension of prosecution[11] .

　　 In the UK, administrative sanctions are positioned as a preliminary stage prior to criminal prosecution, and such sanctions are diverse[12]. These include: ① Inspection and Follow-up, ② Prohibition/Improvement Notices, ③ Detention of Vessels, ④ Notification of Concern (NOC), ⑤ Simple Caution, ⑥ Inquiry into Fitness to hold a Certificate of Competency (CoC). The authority to take these measures is vested in MCA under the MSA 1995[13] .

    Furthermore, when deciding whether to prosecute, MCA, like CPS, considers whether the Full Code Test[14] has been met[15] .

MCA must be satisfied that there is a realistic prospect of conviction and that the evidence is reliable and credible[16]. The assessment is made in two stages, as follows.

  (1) The evidential stage

 The MCA must be satisfied that there is sufficient evidence to give rise to a realistic prospect of conviction in respect of each defendant and each charge. This requires an objective assessment of the evidence, examining its admissibility, reliability and credibility. Furthermore, MCA must consider the existence of any other material that may affect the sufficiency of the evidence.

  (2) The public interest stage

 Where there is sufficient evidence to give rise to a realistic prospect of a conviction, MCA considers whether prosecution is necessary in the public interest.

 In making this determination, MCA takes into account the following factors set out in the guidelines:

 – The seriousness of the offence

 – The degree of the suspect’s culpability

 – The circumstances of the victim and the extent of the harm

 – The suspect’s age and maturity at the time of the offence

 – Whether prosecution is a proportionate response

 – Whether protection of the source of information is necessary

　　In practice, MCA often decides not to prosecute from the perspective of the public interest. Instead of prosecution, a warning is issued to the party who committed the offence. If the warning is not heeded, prosecution may follow.

3. Suspension of Sentence

　　　 A system of suspended sentences also exists in the UK. The legal basis for this is the Sentencing Act 2020[17]. Section 277 of that Act provides that where a defendant is sentenced to a term of imprisonment of not less than 14 days and not more than two years, a suspended sentence order may be made (subsections 1 and 2 of that section). Furthermore, section 286(1) of the Act defines a suspended sentence order, whilst section 288(1) stipulates that a suspended sentence order must specify an operational period, which must be for a period of not less than six months and not more than two years.

　　Furthermore, conditions such as community service may be attached to a suspended sentence[18] .

4. Summary

　　　As outlined above, unlike in Japan, in the UK, MCA, rather than the Crown Prosecution Service, is responsible for the entire process from investigation through to prosecution and the conduct of proceedings. On the other hand, the framework comparable to suspension of prosecution appears broader than that in Japan when administrative sanctions are taken into account. Furthermore, whilst the system of suspended sentences is similar to that in Japan, it is made clear in the legislation that, in addition to a simple suspension of sentence, conditions such as community service may be imposed.

 Part 2: Establishment of Offences Related to Maritime Accidents

  In the following, regarding the offences that may arise in the event of a collision, as mentioned in the previous report, we shall first examine the constituent elements and specific examples, and then discuss their applicability to Maritime Autonomous Surface Ships (MASS).

1. Offences under the Merchant Shipping (Distress Signals and Prevention of Collisions) Regulations 1996

　　Section 6 of the Merchant Shipping (Distress Signals and Prevention of Collisions) Regulations 1996 (hereinafter referred to as ‘the Regulations 1996’) provides as follows.

  (1) Persons subject to liability

    (i) the owner of the vessel concerned; (ii) the master; or (iii) the person responsible for the operation of the vessel at that time. As legal entities are not excluded from (i), this includes legal entities. (iii) includes any person making substantive decisions regarding the navigation of the vessel.

  (2) Conduct

 A breach of the Regulations 1996. Specifically, breach of the International Regulations for Preventing Collisions at Sea (hereinafter ‘COLREG’) may constitute an offence.

  (3) Mental element

　　 A. Regarding mens rea

 In the UK, a subjective element known as mens rea has traditionally been required. A brief explanation of this subjective element in the UK context is provided below.

 Mens rea is described as a psychological element; it was formerly known as ‘malice aforethought’ and is often translated in Japan as ‘criminal intent’ or similar terms. In other words, it encompasses not only conscious planning or deliberate intent, but also blameworthy mental states that are less intentional, such as recklessness or negligence[19]. Recklessness implies an awareness of the danger of the consequences.

Offences that do not require proof of mens rea are referred to as absolute liability offences. Furthermore, offences where proof of mens rea is not required for part (though not all) of the criminal act (actus reus), or where the defence must rebut the absence of criminal intent after the prosecution has completed its case, are referred to as strict liability offences[20].

 Unless a crime is expressly provided not to require mens rea, the requirement of mens rea is implied by law[21].

　　 (b) The mental element under Regulations 1996

　　　　　Section 6(2) of the Regulations 1996 provides: ‘A person charged under these Regulations may raise as a defence that he took all reasonable precautions to prevent the occurrence of the contravention.’ Thus, the commission of the offence is negated by proving that reasonable precautions were taken. In the UK, this is known as the ‘due diligence defence’. Given that this is provided in the text of the Regulations 1996, this offence is regarded as one of strict liability[22] .

  (4) Penalty

  On conviction on indictment, the penalty is imprisonment for a term not exceeding two years and a fine (subsection 1 of the same section).

 Furthermore, on summary conviction, the penalty for a breach of COLREG Rule 10(b)(i) is a fine not exceeding £50,000, and in all other cases, a fine not exceeding the statutory maximum. Furthermore, in the United Kingdom, the Legal Aid, Sentencing and Punishment of Offenders Act 2012 removed the upper limit on fines, thereby allowing fines to be imposed without limit (section 85 of that Act).

  (5) Specific examples

　　  For example, the following case has been reported:[23]

　　 　[Court] Folkestone Magistrates’ Court

 [Date of hearing] 15 February 2011

 [Date of Offence] 22 March 2009

 [Charge] Breach of COLREG Rule 10(d)

 [Case Details] On 22 March 2009, whilst the Belgian trawler De Zwerver was sailing from Milford Haven to Belgium, it was detected by the Dover Channel Navigation Information Service (CNIS) navigating within the English coastal side of the Inshore Traffic Zone off Brighton; subsequently, the vessel’s movements within the inshore traffic zone continued to be monitored by Dover CNIS. Even upon reaching the waters off Dover Port, De Zwerver was still navigating within the inshore traffic zone, and during this time, the vessel had a near-miss (an incident where a collision was narrowly avoided) with a car ferry.

 The ferry was forced to take evasive action to avoid De Zwerver, and the ferry’s master reported the incident to Dover CNIS. De Zwerver continued to navigate within the Inshore Traffic Zone thereafter. During its voyage, radio calls were made to the vessel, but there was no response. Following the incident, attempts were made to contact the shipowner and the skipper, but these also went unanswered.

 [Penalties] The skipper (in this case, the captain of De Zwerver) was fined £400, ordered to pay costs of £600 and tax of £15, whilst the company was fined £1,500, ordered to pay costs of £3,733 and tax of £15.

　　　　Thus, it is not only individuals but also legal entities (shipowners) that are considered to be those responsible for the offence. As it is the skipper who is in charge of navigating the vessel, one might assume that a breach of COLREG Rule 10 would normally be attributed solely to the skipper. However, in the UK, the safety management and operational policies of a vessel are considered to be the responsibility of the company; consequently, a breach by the skipper is often presumed to be the result of deficiencies in the company’s management system, and matters such as route selection, navigation policies and safety management systems are frequently regarded as falling within the company’s sphere of responsibility[24].

2. Offences under section 58 of the Merchant Shipping Act 1995

　　　The Merchant Shipping Act 1995 (hereinafter referred to as ‘MSA 1995’) stipulates in section 58, under the heading ‘Offences by seafarers and others’, that acts endangering a ship, structure or person constitute an offence. Here, we shall focus specifically on those provisions relating to collision accidents.

  (1) Persons subject to liability

　　　 The master of a British-registered ship or a seafarer employed on that ship, etc. (subsection 1 of the same section).

  (2) Conduct and Consequences

　　 A. Conduct (acts[25] and omissions[26] )

 Although paragraph 2 of the same section lists several acts, in relation to collision accidents, the requirements are: (i) where an act is committed on board the ship or in the immediate vicinity thereof which causes the death or serious injury of a person; or (ii)-1 where an act is committed which causes the death or serious injury of a person on board the ship,②-2: where the vessel causes the loss, destruction or serious damage of another vessel or structure, or causes the death or serious injury of a person not on board, where the shipmaster has failed to take the necessary measures to prevent such an event. (1) provides for acts, whilst (2) provides for omissions.

   (b) Breach of duty or failure to perform duties (discharges any of his duties, fails to discharge any of his duties), etc.

　　　　 In the performance of his duties or other functions relating to the operation, machinery or equipment of the vessel, if he acts in a manner that causes or is likely to cause the loss, destruction, death or injury listed in subsection (2)(a) of the same Article (subsection (4)(a) of the same section), or where, by failing to properly perform such duties or functions, similar consequences occur or are likely to occur (subsection (4)(b) of the same section), also constitute criminal offences.

　　　　The difference from (a) is likely that (a) refers to cases where a direct act is performed or omitted, whereas (b) appears to refer to cases where a result arises incidentally to a duty of office or as a consequence of a failure to fulfil a duty of office.

 (3) Mental element, etc.

　　　 With regard to (2)(a) above, it is stipulated as a condition that the act or omission was deliberate or constituted a breach or neglect of duty (subparagraph (a) of subsection 3 of the same section)[27] . Regarding (2)(b) above, these requirements are not imposed.

　　　This is a requirement relating to the mens rea discussed in 1(3)(a) above.

      However, as with section 6(2) of the Regulations 1996, where an act or omission is deemed to constitute a breach of duty or negligence, the offence does not stand if it is proved that the defendant took all reasonable steps to fulfil their duties. This appears to be similar to whether or not an act to avoid the result was performed in the context of negligence offences in Japan (in that sense, although it is not a matter of subjective intent, it is described here in relation to the provisions).

  (4) Penalties

　　 In summary proceedings, the penalty is a fine not exceeding the statutory maximum (subsection (a) of the same section); in proceedings by indictment: imprisonment for a term not exceeding two years, or a fine, or both (subsection (b) of the same section).

  (5) Specific Examples

　　For example, if a watchkeeper is reading cargo-related documents at the rear of the bridge and a fatal collision occurs with a fishing vessel operating ahead, it would appear that this constitutes a failure to fulfil the duty to keep a proper look-out and a failure to properly perform the duties prescribed in section 58. However, given that the incident resulted in a fatality, it would also appear to fall under the offence of Gross Negligence Manslaughter (hereinafter referred to as ‘GNM’), as described below. The determining factor in establishing which offence applies is the presence or absence of gross negligence.

3. Gross Negligence Manslaughter

　　The offence of gross negligence manslaughter is based on case law rather than statutory law. According to R v Adomako [1995] 1 AC 171, the following elements are required: (a) that the defendant owed a duty of care to the deceased; (b) that the defendant breached that duty of care through a negligent act or omission; (c) that the negligent act or omission caused the death; and (d) that the negligence causing the death amounted to gross negligence and was therefore criminal[28] .

  (1) Persons subject to liability

　　　The persons subject to liability must be a natural person; legal entities are excluded. Furthermore, regarding the causing of death through negligence by a legal person, the question arises as to whether the offence of corporate manslaughter (an offence under the Corporate Manslaughter and Corporate Homicide Act 2007) has been committed.

  (2) Conduct and Consequences, etc.

　　　 The prosecution must establish that the defendant owed a duty of care towards the victim, that this duty was breached through a negligent act or omission, and that death occurred (see (a) and (b) above). Injury is not covered by this offence.

 The breach must be such that a serious and obvious risk of death was reasonably foreseeable.

 Furthermore, the breach of the duty of care must be so serious (i.e. criminal) as to be reprehensible. This point was defined in Adomako [1994] 3 All ER 79 as follows: ‘Was the defendant’s conduct, in the light of the risk of death, so reprehensible as to amount to a criminal act or omission in all the circumstances? The prosecution must prove the following two elements: (i) that there were circumstances such that a reasonably prudent person in the defendant’s position would have foreseen that the defendant’s act or omission would give rise to a ‘serious and obvious risk of death’ ; and (ii) that the breach of the duty of care was, in all the circumstances, so grossly out of line with the standard expected of a person of the defendant’s standing, experience and responsibility as to be reprehensible and amount to a criminal act[29] .

  (3) Causation

      It is necessary that the act or omission be the cause of death (see (c) above).

 (4) Mental Element

　　 It is required that the negligence causing the death constitutes gross negligence[30] . In determining whether there is a realistic prospect of conviction, the prosecutor must also take into account how the courts have historically assessed the degree of negligence required for this offence[31] .

  (5) Penalty

　　　GNM is a common law offence, and the maximum sentence is life imprisonment. The sentencing range is as reported in the previous report; sentencing varies significantly depending on the degree of negligence (A–D), with a starting point of 2–12 years and a final range of 1–18 years being the standard (it is explicitly stated that the possibility of life imprisonment exists within the system)[32] .

  (6) Specific Examples

　　　Although it appears rare for GNM to be established in relation to ship collisions, the following case exists:

　　[Case]

　　　This case concerns the collision that occurred on 10 March 2025 in the North Sea off the coast of the United Kingdom between the container ship Solong (registered in Portugal), which was underway, and the tanker Stena Immaculate (registered in the United States), which was at anchor, resulting in the death of Mark Pernia, a crew member of the container ship Solong[33] . The defendant is Motin (a Russian national), the master of the Solong.

　　[Facts constituting the offence]

　　　 It is stated that, in order to secure a conviction, the prosecutor was required to argue and prove the following elements.

 (1) That the defendant had a duty of care towards Mark Pernia.

 (2) That he breached that duty by failing to take any action to prevent the collision.

 He had ample opportunity to prevent the collision, but failed to do so.

 (3) At the time of the breach of duty, there was a serious and obvious risk of death

 (4) The breach of duty caused or significantly contributed to the death.

 The prosecution clearly argued that this was the cause of Pernia’s death.

 (5) The negligence must be ‘genuinely and exceptionally grave’.

 Despite clear visibility, a functioning radar warning system and multiple warnings, Motin failed to alter course, reduce speed or sound the alarm.

 The prosecution also demonstrated that Motin was solely in charge of the vessel’s navigation, that he ignored radar and tracking data, failed to avoid the Stena Immaculate, did not stop the vessel, and did not issue a warning to his crew or the other vessel.

 The jury was shown that the Solong had been heading straight towards the anchored Stena Immaculate for more than 30 minutes and that it was visible to the naked eye 12 minutes before the collision. There was no reasonable explanation for his failure to act. Data from the black box showed that no course changes or speed adjustments had been made prior to the collision. The equipment was functioning normally, and Motin’s claim of ‘rudder failure’ was completely unfounded. Furthermore, Motin had disabled the Bridge Watch Alarm System (BNWAS) and was on watch alone, contrary to standard safety procedures[34] .

  Furthermore, regarding sentencing, the court issued Sentencing Remarks[35] . In these remarks, the guidelines[36] classify culpability into four categories (very high, high, moderate, low) and that, in making this assessment, the issue was what actually occurred during the defendant’s watch on 10 March 2025: (i) whether the defendant neglected to maintain a proper lookout and failed to notice the impending disaster until just before the collision, or (ii) whether, whilst paying some attention to basic lookout duties, he lacked the ability to navigate safely, and, furthermore, disregarded the lives of the crew of the Solong and the Stena Immaculate, failing to sound any alarm before ramming the tanker at full speed of 16 knots; and, on this point, the court ruled that the defendant had seriously failed to recognise the danger of collision and, as a result, took no action whatsoever to avoid the collision. The court further stated that, whilst this case fell just short of the level of ‘blatantly disregarding a very high risk of death’, the difference was not significant. In conclusion, the offence was classified as ‘moderate culpability’ under the guidelines (although, prior to the consideration of mitigating factors, the case was deemed to fall at the ‘upper end’ of the moderate culpability category).

  Taking into account the mitigating circumstances[37], a prison sentence of six years was imposed, with 11 months of pre-trial detention credited; it was indicated that parole would be possible upon completion of three-quarters of the sentence.

  (7) Distinction between the offence under section 58 of the MSA 1995 and GNM

The offence under section 58 covers not only death but also injury. On the other hand, GNM is limited to death only.

　　　　With regard to the acts involved, both include both acts and omissions. As the offence under section 58 targets negligence in the performance of duties, and GNM requires that a duty of care towards the victim be established, the two appear to overlap in substance.

 However, under GNM, it is required that the breach of the duty of care was such that it was reasonably foreseeable that it would give rise to a serious and obvious risk of death. Furthermore, it is held that the breach of the duty of care must be sufficiently serious to amount to a criminal act or omission.

 Whilst GNM relates to offences against the person, the offence under section 58 is listed alongside other categories of conduct for which a fatal or injurious outcome is not required; consequently, it is considered to have an aspect of punishing a breach of regulations or the creation of a danger.

4. Corporate manslaughter under the Corporate Manslaughter and Corporate Homicide Act 2007

　　　As noted in the previous report, the Corporate Manslaughter and Corporate Homicide Act 2007[38] is new legislation establishing the offence of corporate manslaughter.

  (1) Entities subject to liability

　　　The entities subject to criminal liability are: (a) legal entities; (b) government departments and other bodies listed in Schedule 1; (c) the police; and (d) partnerships, trade unions or employers’ organisations acting as employers (section 1(2) of the Act).

　　　Furthermore, for this offence to be established, the way in which the organisation’s activities are managed or organised by its senior management must be a substantial element in the breach (section 1(3) of the Act).

　　　 ‘Senior management’ refers to persons who, with regard to the organisation’s activities as a whole or a significant part thereof, (i) play a significant role in decision-making regarding management or operational methods, or (ii) actually manage or operate those activities as a whole or a significant part thereof (section 1(4)(c)). This is understood to include not only those belonging to the direct line management structure, but also those who play strategic roles or roles relating to regulatory compliance [39] .

  (2) Conduct and Consequences

　　　With regard to the result, the manner in which the organisation’s activities are managed or operated must cause the death of a person (section 1 of the same act).

　　　　Acts can be categorised as follows.

 The manner in which the organisation’s activities are managed or operated must constitute a serious breach of the relevant duty of care owed by the organisation to the victim (paragraph 1 of the same section).

 The specific content of the relevant duty of care is set out in sections 2 and 3 to 7 of the Act (section 2(4)(a)).

A breach of the duty of care by an organisation is considered ‘gross’ where the breach deviates significantly from the standard reasonably expected of the organisation in the circumstances (subparagraph (b) of the same paragraph)

  (3) Mental element

       There appears to be no requirement for a subjective element. The focus appears to be solely on whether the breach of the relevant duty of care by a senior manager was gross.

  (4) Penalty

　　　　 An organisation found guilty of corporate manslaughter following an indictment shall be liable to a fine (section 6). There is no upper limit on the fine; it is unlimited.

5. Summary

　　　As summarised above, in the UK, there are many situations in which criminal liability may arise from a collision involving a vessel. With regard to the parties liable, the offence of breaching the Regulations 1996 includes the shipowner, and the scope of punishment has been extended to include legal entities. Furthermore, in the UK, fines are often unrestricted and tend to be substantial (in addition, the costs associated with criminal proceedings are high and are often imposed as additional penalties). The offence of Gross Negligence Manslaughter (GNM) excludes injury from its scope; in that sense, its scope of application is narrow. Furthermore, as the requirements regarding seriousness and other factors are limited to a narrow range, it appears that the scope of application is relatively narrower than that of the offence of professional negligence causing injury in Japan. However, once this offence is established, the maximum statutory penalty is life imprisonment, making it a severe offence.

 Part 3: MASS and Criminal Liability in the UK

1. Events That May Arise in the Operation of MASS

 Traditionally, navigation was carried out on the bridge. However, with the operation of MASS, navigation is carried out either by a Remote Operation Centre (hereinafter referred to as ‘ROC’) or autonomously by the vessel itself.

 Consequently, on such vessels, the bridge may be temporarily unmanned, or personnel may be able to engage in other tasks or take breaks in the area behind the bridge.

 On the other hand, potential problems include: (i) the impact of communication delays on navigation; (ii) the inability to navigate due to the loss of the main power supply or similar; (iii) the inability to navigate due to a system shutdown; (iv) a lack of proficiency in remote operation; (v) failure to respond to fallback procedures; and (vi) system defects. These are issues that were not anticipated in the era before remote operation or MASS.

 In the following, due to space constraints, we will examine the existence of criminal liability under English law, focusing on ROC operators, in cases where circumstances (i), (iv) and (vi) occur and result in death or injury.

2. (1) Where death or injury results from communication delays affecting navigation

 (1) Whether a communication delay may give rise to criminal liability

　　　A communication delay between ROC and the vessel does not in itself immediately constitute an offence. However, even in the case of a communication delay, if it affects the navigation of the vessel and the vessel falls within the category of a vessel not under command (Rule 3(f) of COLREG), but fails to display the statutory lights required for such a vessel, a breach of Rule 27 of COLREG may be an issue.

 (2) Offences that may arise in the event of a breach of Rule 27(a)

 (a) Offence under the Regulations 1996

　　In the UK, as discussed in sections 2 and 1 above, a breach of the COLREG may constitute a breach of section 6 of the Regulations 1996. In cases where a vessel is being operated remotely from the ROC, the ROC staff member responsible for the command and control of the vessel is likely to fall within the scope of the phrase “the master and any person for the time being responsible for the conduct of the vessel” in that Regulation. This is because section 313(1) of the MSA 1995, which forms the legal basis for the Regulations 1996, defines the term ‘master’ as including the master or any person in charge of the command or management of the vessel (excluding pilots), and, in the case of fishing vessels, as meaning the skipper; consequently, an ROC operator may also fall within the definition of ‘master’. However, as the defence of reasonable precaution (section 6(2) of the Regulations 1996) is recognised, if adequate safeguards have been put in place regarding communication delays, and a communication delay occurs despite these measures, the offence will not be established. On the other hand, if adequate measures were not taken despite the possibility of communication delays being foreseeable, this defence may not hold.

 (b) The offence under section 58 of the MSA 1995

　　When considering a violation of section 58 of the MSA 1995, the question arises as to whether an ROC operator falls within the scope of the master of a British-registered ship or a seafarer employed on that ship, as referred to in subsection (1) of that section. On this point, as discussed in (a) above, the concept of ‘master’ is defined in section 313 of the MSA 1995 and is a concept that may encompass an ROC operator. Furthermore, it appears that the definition of ‘seafarer’ may also encompass such operators.

　　Furthermore, as the display of the lights or shapes specified in Rule 27 of the COLREG is the duty of the ROC operator who is in command of and supervising the navigation of the vessel, the failure to display those lights or shapes may constitute a breach of duty (subsection (4) of the same section).

 (c) Gross negligence manslaughter　　

  For this offence to be established, as discussed in sections 2 and 3 above, it is required that it was reasonably foreseeable that the breach of the duty of care would give rise to a serious and obvious risk of death.

 Furthermore, the breach of the duty of care must be sufficiently serious to amount to a criminal act or omission. Specifically, the following requirements must be met: (i) there must be circumstances indicating that a reasonably prudent person in the defendant’s position would have foreseen that the defendant’s act or omission would give rise to a ‘serious and obvious risk of death’; and (ii) the breach of the duty of care must, in all circumstances, have deviated significantly from the standard expected of a person with the defendant’s qualifications, experience and responsibilities, to the extent that it was reprehensible and amounted to a criminal offence.

 Consequently, it is considered that the mere possibility of a delay in communication would not satisfy these requirements. Furthermore, as the offence under GNM can only be established where death has occurred, it is not punishable where the result is bodily injury.

　　(d)Corporate manslaughter under the Corporate Manslaughter and Corporate Homicide Act 2007

　　　　This offence may be established where an operator of an ROC, or a person in a position to ensure the integrity or redundancy of communications, qualifies as a senior manager, and the manner in which the organisation’s activities were managed or operated constitutes a serious breach of the relevant duty of care owed by that organisation to the victim. However, since a senior manager is defined as a person who, in relation to the organisation’s activities as a whole or a significant part thereof, (i) plays a significant role in decision-making regarding the management or operation of those activities, or (ii) actually manages or operates those activities as a whole or a significant part thereof (section 4(c) of the Act), it is not sufficient merely for an ROC operator to be directing and supervising the navigation at the scene.

3. (4) Lack of proficiency in remote operation

  (1) Does a lack of proficiency in remote operation constitute a criminal offence?

　　　  In the UK, ROC operators are required to hold appropriate qualifications and training (The Workboat Code Edition 3, Annex 2 Remotely Operated Unmanned Vessels, Section 7.2.5). Details are set out in MGN 703[40], Section 7. Annex A – Training in remote operations.

      　On the other hand, the term ‘proficiency’ appears in section 7.12.1 of the same document: Coordinate Remote Operator familiarisation.

　　　　While a lack of proficiency in itself does not appear to constitute a criminal offence, where such a lack leads to non-compliance with the COLREG, it may constitute an offence under Regulations 1996, section 6 of the Regulations 1996. Furthermore, with regard to section 58 of the MSA 1995, where a failure to fulfil the duties required by one’s position is deemed to have occurred, and where this results in death or injury, there appears to be scope for a breach of that section to be established. On the other hand, offences under the Corporate Manslaughter and Corporate Homicide Act 2007 are defined such that a gross breach of the duty of care by an organisation occurs when the breach deviates significantly from the standard reasonably expected of the organisation in the circumstances. Therefore, it seems unlikely that a breach of this Act would occur if the training required by the MGN had been carried out. Furthermore, GNM holds that the breach of the duty of care must be sufficiently serious to amount to a criminal act or omission; it must satisfy the requirement that: (i) there were circumstances such that a reasonably prudent person in the defendant’s position would have foreseen that the defendant’s act or omission would give rise to a ‘serious and obvious risk of death’; and (ii) the breach of the duty of care deviated significantly from the standard expected of the defendant’s qualifications, experience and responsibilities, and was reprehensible and criminal in nature. The question is what standard is required of ROC operators; however, regarding COLREG, if the same standard of navigational manoeuvring as that required of ordinary seafarers is expected, it is thought that whilst such an offence would rarely be established, it cannot be said that there are absolutely no circumstances in which this offence could be established.

4. (ⅵ) System Defects

　　As software developers do not directly command or manage the navigation of a vessel, it is highly likely that they do not fall within the scope of ‘any person for the time being responsible for the conduct of the vessel’ under section 6(1) of the Regulations 1996. Furthermore, as they do not fall within the scope of ‘all seafarers employed on a British-registered ship’ under section 58 of the MSA 1995, it appears difficult for that provision to apply. Furthermore, regarding the application of GNM, it must be established that, at the time of programme design: (i) a reasonably prudent person in the position of a software developer would have foreseen that their acts or omissions would give rise to a serious risk of collision; and (ii) the breach of the duty of care was, in all the circumstances, such that it deviated significantly from the standard expected of a software developer’s qualifications, experience and responsibilities,  and was reprehensible and criminal in nature; however, as software developers would typically design software to comply with COLREG and other relevant regulations, it is generally considered that GNM would not apply. However, in specific situations where, despite reports of a risk of collision, evasive manoeuvres by other vessels, or the fact that an accident actually occurred due to autonomous navigation, no modifications were made to the software, it seems conceivable that GNM could be recognised based on the circumstances at that particular point in time.

4. Comparison with Japan

  As outlined above, this report has been able to provide a more detailed and specific account based on legal grounds and facts than the previous one.

1. Procedural Aspects

　　  Compared to Japan, where the institution of public prosecution is the exclusive prerogative of public prosecutors, a major difference with the UK is that there is no such monopoly, and private prosecution is widely recognised (whether prosecution should be widely permitted to members of the public or should be the exclusive prerogative of specific bodies is difficult to judge as superior in all cases, given a country’s culture and historical context[41]).

　　  With regard to the suspension of prosecution, a pathway to non-prosecution remains available for certain types of cases; the aim of achieving a general deterrent effect without imposing a penalty is similar to that in Japan.

　　　Furthermore, where prosecution is brought, the fact that MCA itself is responsible for prosecuting offences under the Regulations 1996 and the MSA 1995 represents a significant difference from Japan’s system of exclusive prosecution by public prosecutors. It is difficult to make a definitive judgement as to whether the Japanese or British system is superior. However, in the UK, as the agency that conducts the investigation proceeds directly with the prosecution and remains in charge until the proceedings are concluded, it can be said that there is a fertile ground for MCA to demonstrate its expertise in relation to laws falling within its own law enforcement remit. On the other hand, it appears that the Regulatory Compliance Investigations Team (RCIT), which was mentioned in the previous report, exists within MCA to complement the need to ensure that general rules regarding prosecution (decisions) are properly implemented. From this perspective, it might also be useful in Japan to actively seek the opinions of experts in maritime law interpretation, who possess a certain level of understanding regarding negligence under criminal law, when making decisions on whether to prosecute or not.

 It should be noted that, although not addressed in this report, whilst the objective elements of Maritime Accident Investigation Branch (MAIB) reports may be applied to criminal proceedings, those elements relating to the assessment of negligence are generally considered inapplicable.

　　　On the other hand, prosecution for GNM is to be carried out by Crown Prosecution Service (hereinafter ‘CPS’), a point which is similar to the system in Japan.

2. Substantive Aspects

　　In the field of substantive law, it is significant that in the UK, it is possible to impose penalties on shipowners for offences under the COLREG. In Japan, attention tends to focus on the liability of individuals for negligence; however, even individuals are, in the first place, operating the vessel only as members of a company or the vessel’s operational organisation, and it is thought that a significant proportion of the factors determining whether safe operation is possible depend largely on training provided by the company and organisational measures. It may not be an appropriate approach to attribute such issues to the negligence of individuals (seafarers) in the sense of a deviation from their objective duty of care.

　　In Japan, the offence of causing danger through negligence in the course of business (Article 129 of the Penal Code) is not punishable in respect of legal entities. Although Japanese law also provides for corporate penalties in legislation such as the Ship Safety Act, the fines are kept to a minimum, and these provisions are not directly related to the occurrence or prevention of collision accidents (although there are provisions in Article 69 of the Ship Safety Act Enforcement Regulations, these appear to be based strictly on vicarious liability).

　　In the UK, as noted in the previous report, corporate manslaughter was legislated over a period of more than 20 years following the Herald of Free Enterprise incident. Although no immediate examples of its application in subsequent accidents have been found, there are cases where the law has been applied in other fields. While the threshold for meeting the requirements for senior management is high, combined with the increase in the level of fines, it is thought that a certain general deterrent effect (in the context of this paper, the prevention of collision accidents) may be occurring.

　　In Japan, too, it seems appropriate to give substance to general deterrence through fines; that is, to increase the level of fines to a degree that produces a deterrent effect.

3. Regarding MASS

　　In Japan, regarding the criminal liability of ROC operators in the event of a collision, the offence of professional negligence causing danger to navigation is based on an ‘open’ definition of negligence. Consequently, provided that a duty to foresee and a duty to avoid the result are specifically recognised, there are no particular constraints on the determination of guilt or innocence. Rather, if the distinction is limited to whether an ROC operator conducts the navigation from the bridge or via the ROC, there would likely be no significant difference in the duties imposed. In the UK, although the Regulations 1996 also limit the scope of the subject, it appears possible to interpret the term ‘master’ as including an ROC operator. Furthermore, it is said that a breach of section 58 of the MSA 1995 can also be interpreted as falling within the scope of employment.

　　In the UK, it would generally appear difficult to hold developers liable for software defects. This is similarly the case in Japan; as holding software developers liable requires specific foreseeability of a collision occurring, there is a certain threshold for negligence to be recognised. On the other hand, once an accident has occurred due to a software ‘defect’, rectification of the defect will be required (although it is likely that identifying the cause of such a defect and repairing it will present certain difficulties; consequently, software developers are required to design systems on the premise that programme defects will need to be rectified).

 End of report

[1] Unless otherwise stated, the following refers to England and Wales.

[2] It is also stated that ‘the right of an individual to bring a private prosecution has often been defended as an important and historic constitutional right acting as a “bulwark against the inaction of the authorities”’ (p. 10, ‘House of Commons Justice Committee: Private prosecutions: safeguards, Ninth Report of Session 2019–21’, https://committees.parliament.uk/publications/2823/documents/27637/default/

[3] For the current state of private prosecutions in the UK, see “2 The state of private prosecutions”, https://publications.parliament.uk/pa/cm5801/cmselect/cmjust/497/49705.htm#footnote-131

[4] See note 2 above

[5] In Japan, Article 247 of the Code of Criminal Procedure stipulates that “public prosecutions shall be conducted by public prosecutors”, and all prosecutions are therefore conducted by public prosecutors.

[6]  https://www.gov.uk/government/organisations/maritime-and-coastguard-agency

[7]  https://www.legislation.gov.uk/ukpga/1995/21/contents

[8]  https://www.legislation.gov.uk/ukpga/1995/21/section/256

[9]  Although these points were not clear in the previous report, they have become apparent as a result of this investigation.

[10]  https://www.gov.uk/government/publications/mca-enforcement-policy-statement/mca-enforcement-policy-statement

[11]  In Japan, the principle of discretionary prosecution (Article 248 of the Code of Criminal Procedure: ‘Where, in view of the character, age and circumstances of the offender, the gravity and circumstances of the offence, and the situation following the offence, prosecution is not deemed necessary, a public prosecution may be waived’) is adopted. Consequently, public prosecutors have broad discretion regarding whether or not to prosecute. In fact, 56.1% of final dispositions by the Public Prosecutors’ Office are cases where prosecution is suspended(https://hakusyo1.moj.go.jp/jp/71/nfm/n71_2_2_2_4_0.html).

[12]  See note 10 above

[13]  However, this study did not clarify whether simplified warnings fall within the authority granted under the MSA 1995.Furthermore, regarding simple cautions, the document “Simple Cautions for Adult Offenders” (https://assets.publishing.service.gov.uk/media/5afeacfc40f0b6561ce44093/cautions-guidance-2015.pdf) states that agencies with prosecutorial authority may issue simple cautions.

[14]  https://www.cps.gov.uk/publication/code-crown-prosecutors#section4

[15]  See note 10 above

[16]  See note 10 above

[17]  https://www.legislation.gov.uk/ukpga/2020/17/contents

[18]  https://www.legislation.gov.uk/ukpga/2020/17/schedule/16

[19]  https://www.iclr.co.uk/knowledge/glossary/mens-rea-and-actus-reus/

[20]  Ibid.

[21]  In Sweet v Parsley [1970] AC 132, the House of Lords held that, in the absence of special reasons, mens rea is an essential element of every offence, and that the courts should not interpret an offence as one of absolute liability unless it can be established that Parliament intended it to be so.

[22]  In Japanese law, strict liability is primarily found in the field of civil liability.

[23]  https://assets.publishing.service.gov.uk/media/5a7edde4ed915d74e6226f66/mca_prosecutions_2011.pdf

[24]  In this case, it appears to have been found that there were problems with the company’s safety management system. This is also reflected in the high fine imposed on the company.

[25]  The original text states “does any act”; to clarify the distinction from paragraph 4, this has been translated as “act”.

[26] The original text states “omits to do anything required”; to clarify the distinction from paragraph 4, this has been translated as “omission”.

[27]  Paragraph (b) stipulates that intent or negligence is not required if ‘the master or seafarer was under the influence of alcohol or drugs at the time of the act or omission’.

[28]  https://www.cps.gov.uk/prosecution-guidance/gross-negligence-manslaughter

[29]  Ibid.

[30]  Although I have provisionally classified this under the subjective aspect, since GNM does not require mens rea as a prerequisite, gross negligence appears to be closer to an objective breach of a duty to act.

[31]  See note 29 above

[32]  https://sentencingcouncil.org.uk/guidelines/gross-negligence-manslaughter

[33]  https://www.cps.gov.uk/cps/news/north-sea-boat-crash-captain-convicted-over-exceptionally-bad-negligence-leading-death

[34]  Regarding the above, see the same source: https://www.cps.gov.uk/cps/news/north-sea-boat-crash-captain-convicted-over-exceptionally-bad-negligence-leading-death

[35]  https://www.judiciary.uk/wp-content/uploads/2026/02/Motin-Feb-2026-Sentencing-Remarks.pdf

[36]  These are the guidelines referred to in (5) above.

[37]  As mitigating factors, the following were taken into account: firstly, that a certain degree of sincere remorse was demonstrated in the letter written to the judge during the proceedings; secondly, that in that letter, the defendant confirmed that he would not return to the sea in future; and thirdly, that as the defendant is a Russian national and his sole reason for staying in this country is to serve his sentence, his life in detention is likely to be more isolated than usual. The fact that the defendant’s status as a foreign national is treated as a mitigating factor is particularly interesting when compared with sentencing practices in Japan.

[38]  https://www.legislation.gov.uk/ukpga/2007/19/contents

[39]  https://publications.parliament.uk/pa/ld200607/ldbills/019/en/07019x–.htm

[40]  https://www.gov.uk/government/publications/mgn-703-information-concerning-the-training-and-competence-of-remote-operators-working-with-remotely-operated-unmanned-vessels-rouvs-certified-und/mgn-703-information-concerning-the-training-and-competence-of-remote-operators-working-with-remotely-operated-unmanned-vessels-rouvs-certified-und#annex-a–training-in-remote-operations

[41]  However, unlike in Japan, the fact that private individuals retain the opportunity to bring charges without going through a prosecution review board is likely to be one of the useful institutional designs for eliminating arbitrariness and unfairness in the prosecution process.