Since Unclos was adopted, high-value submarine infrastructure has become commonplace everywhere. But the convention does not offer adequate protection.

It does remain clear that coastal states have sovereign rights to exploit economic resources within their EEZs, including minerals, oil and gas.

Were another country to interfere with those rights, there would then be domestic jurisdiction. But there is no domestic jurisdiction over interference with comms cables.

“There’s a big gap. Despite the surge in underwater infrastructure, coastal states don’t have the right to protect themselves and have to fall back on the ship’s register.”

Moreover, at the time of Unclos’s adoption, the world fleet was dominated by national flags or long-established open registers that were mindful of necessary standards.

Since then, there has been a proliferation of less-regulated flags with a range of political worldviews. Often their national economies are heavily dependent on their registry.

Sometimes their administrations are commercial companies based in a completely removed geographical location with few links to the place where the damage may have occurred.

Such flags may lack the commercial or political motivation to step into difficult situations.

Eagle S is the first case of this type of which Phillips is aware, and he described it as shining a light on an obvious lacuna in current legal mechanisms.

“It may fairly be said that Unclos is not keeping pace with the world in which we are living,” he said.

“If the international community does not want this to become a flashpoint, it needs to think ahead and plan how this can be regulated better.”

Rewrite Unclos

Rewriting Unclos would be a lengthy and politically fraught process. There are just two ways in which the convention can be amended.

The first is by a conference convened by the United Nations secretary-general at the request of a state party and with the backing of half of the signatories, which number 170. That would at the very least require a huge diplomatic effort.

The other method is a simplified procedure under which any state party can table a proposed amendment. But the wording is adopted only if no other country objects within 12 months.

Either way, the amendment must then be accepted by 60 state parties to enter into force.

A partner at another leading law firm, who preferred not to be named, agreed with his counterpart’s assessment.

“Even though we had the Cold War when Unclos was agreed, generally everybody played by the rules. Western nations dominated the seas and flag states were sensible countries and did what was required of them.

“It never even occurred to the drafters that some people would make mischief and that has left a real hole.”

Shipowners that want to evade the law can easily register vessels in flag states that have no real interest in identifying wrongdoers as long as they pay the registration fees.

If a ship were used to launch drones to attack coastal state airports, that would likely constitute a breach of innocent passage and the vessel could legitimately be detained.

But little can be done about the actions of ships on the high seas, such as industrial trawlers whose crews are subject to modern slavery, unless the flag state comes forward.

The Finnish prosecutors may have had a stronger case against Eagle S if they had been able to demonstrate deliberate malfeasance, which they were not able to do, he added.

The lawyer, who is a former seafarer, commented: “You know when you are dragging your anchor and you can do something about it.

“You shouldn’t need to drag your anchor for 50 or 60 miles unless your main engine is out of action. You simply start your engine and pick your anchor up.

“It does seem unlikely that they were unaware they were dragging their anchor for such a long distance. But I couldn’t, as I read it, identify any malfeasance there.”

He concurred with Phillips on the need to beef up Unclos but assessed the chances of achieving that rapidly as slim, given likely opposition from countries happy with things as they are presently.

Additionally, the US is not a signatory to Unclos, and its president Donald Trump is not an enthusiast for new international agreements.

“The problem is that the whole international system is unravelling. You might get an agreement on deepsea mining because that benefits the Chinese.

“But on this one, I don’t see consensus among flag states who benefit from this situation. The chances of getting amendments passed are really quite remote. We are playing with our hands tied behind our backs.”