Why an autonomous ship does not need a captain

The captain as a given  

Few professions capture the imagination quite like that of a ship’s captain. “Anyone who has ever seen the film Captain Phillips or the Hornblower series knows just how important the role of a ship’s captain is”, says Stevens.  

In law, too, the captain plays a central role. In the past, he even held the power over life and death on his ship. International treaties still impose many obligations on him, ranging from the safety of the ship to the keeping of logbooks. Some of these duties are quite unusual. The captain may refuse the owner’s order to set sail if he does not consider the ship to be safe. He is personally obliged to help anyone in distress at sea. Furthermore, various national laws prohibit him from leaving his ship whilst it is at sea, and in the event of danger, he must be the last to leave the ship.  

In May 2026, the IMO adopted international regulations for autonomous ships, known as the MASS Code. These stipulate that a human captain must always be in charge, even when the ship is being controlled by software.  

What are autonomous ships?

MASS stands for Maritime Autonomous Surface Ships. It is a collective term for civilian vessels with a high degree of automation. Stevens broadly distinguishes three levels. At the lowest level, the crew are on board and uses electronic aids, such as digital nautical charts and systems that warn if another vessel comes too close. This is already standard practice. At the second level, the crew are based in a control centre ashore and operates the vessel remotely. At the highest level, software makes all navigation decisions.  

Incidentally, ‘autonomous’ does not necessarily mean ‘unmanned’. A passenger ship can sail independently while still having a crew on board to look after the passengers. A key driver behind this development is the growing shortage of trained ship officers.  

No task that only a captain can perform

Stevens has examined all the duties assigned to the captain under treaties. He concludes that no maritime duty must, by its very nature, be carried out by a captain. In practice, many duties have already been delegated. The stowage plan, which determines how the cargo is distributed across the ship, has long been drawn up ashore, “without this causing much of a fuss at the time.” British judges have established that, thanks to modern communications, it is now the vessel owner who makes decisions, not the captain. The vessel owner is the company that operates the ship and bears commercial responsibility for it. The vessel owner can provide information to the authorities, and travel data is already automatically recorded in the ship’s black box. According to Stevens, what matters is that a task is carried out, not who carries it out.  

A human as saviour in times of need?

Behind the insistence on having a captain is often the idea that a human must be able to intervene if the technology fails. However, Stevens doubts whether that is realistic. “The more complex a system becomes and the more tasks it takes over from human operators, the more difficult it becomes for the human operator to remain ‘in the loop’.” He points to the Japanese moon lander SLIM, which landed at an oblique angle in 2024, and to the disasters at Chornobyl and on the Deepwater Horizon drilling platform. People were present there too, but they did not realise what was happening in time. Mandating a captain, therefore, does not prevent accidents.  

The risk of a scapegoat

Stevens’s main objection concerns liability. Under civil law, an accident causes few problems, as the vessel owner and his insurer pay for the damage. Under criminal law, the situation is different. Captains are already being prosecuted for matters over which they have little or no control. With autonomous ships, Stevens argues, the captain risks becoming a scapegoat “in the biblical sense of the word.” By this, he means someone upon whom all the sins of a system are laid and who is subsequently sacrificed.  

Just how arbitrary this can be is illustrated by the fact that, in theory, a company could appoint its HR manager as the captain of a fully autonomous ship as early as tomorrow. “As long as everything goes well, it doesn’t mean much, and nobody is bothered by it.” If something goes wrong, however, that person could face criminal charges for something over which they actually had no control. According to Stevens, criminal law should be about individual culpability. If the CEO of a shipping company orders the installation of software enabling the ship to discharge oil illegally, then prosecution is justified. In addition, the government can make shipping companies’ licences subject to conditions, which it can then revoke.  

A designated person rather than a captain

Instead of a captain, Stevens proposes a ‘designated person’, modelled on existing safety regulations in the shipping industry. That person is available to the authorities day and night and has a direct line to the company’s senior management.  

The difference may seem minor, but according to Stevens, it is fundamental. The word ‘captain’ evokes expectations from a time when crews lived together in isolation for months on end, and the captain needed far-reaching disciplinary powers. An employee in a control centre simply goes home after their shift. “If you use a new term, people are forced to ask themselves exactly what that new term entails.”  

Beyond the maritime sector

The same question arises with self-driving cars. Up to what point are you the driver, and from when on are you merely a passenger? Liability does not disappear, says Stevens, but it must serve a purpose. Victims must receive compensation, and incidents must be prevented as far as possible. This requires, above all, technical research aimed at learning, not at pointing fingers. “Liability is not legal sadism.”