Flags, passports and the sea: when Korean courts can try crime at sea
A foreign ship arrived at Okgye Port with 1.7 tonnes of cocaine on board, taken on in the Pacific off Peru; a Korean court sentenced the principal offender to 25 years. Yet in an earlier collision in Korea’s exclusive economic zone that killed Korean fishermen, the Korean courts held that they had no criminal jurisdiction at all. This article explains what makes the difference.
This blog post is an English translation of a Korean-language column the author contributed to the Korea Shipping Gazette on 6 July 2026. The translation is the author’s own; in the event of any discrepancy, the Korean original prevails.
A record cocaine seizure at Okgye
Last year, at Gangneung, there occurred the largest case of cocaine smuggling into the country since the founding of the nation. Some 1.7 tonnes of cocaine were detected on board a foreign ship that had entered Okgye Port, and the defendants were all foreign seafarers. The place where the defendants took delivery of the cocaine was on the high seas near Peru, and the ship carried the cocaine across the Pacific and into Korea. The Korean court sentenced the principal offender, a foreign seafarer, to 25 years’ imprisonment. How was a Korean court able to punish a foreigner, on a foreign ship, in respect of narcotics obtained outside our country?
Is a ship really “floating territory”?
When ship-related crime and crime at sea are discussed, the expression that appears most often is that “a ship is floating territory”. That is because of the flag State principle — that is, because as a general matter the law of the ship’s State of nationality applies. Our Criminal Act, too, provides that Korean criminal law applies even to a foreigner who commits an offence on board a Korean ship. Half of that saying, however, is not true. Not everything that happens on board a ship is judged by the same yardstick. In ship-related crime and crime at sea, the character of the incident matters as well, along with whether the sea in which it occurred is high seas or territorial sea and where the nationalities of those involved lie.
On the high seas, the flag State rules — and drugs are no exception
We look in turn at the case of the high seas, the case of our territorial sea and the case of a foreign territorial sea. The high seas are a space over which the sovereignty of no State extends, and in respect of a ship navigating there jurisdiction is in principle exercised by the ship’s State of nationality and by the offender’s State of nationality. Accordingly, even where a collision or other navigational casualty occurring on the high seas gives rise to criminal liability on the part of the master or the crew, criminal proceedings cannot be brought anywhere other than in the ship’s State of nationality or the offender’s State of nationality.
A Korean court has confronted this question squarely. The case concerned a foreign-flagged container ship which collided with a Korean fishing vessel in Korea’s exclusive economic zone, the master and crew of the fishing vessel dying and the vessel sinking. Because the fishing vessel with which she collided was a Korean ship and the deceased were Korean nationals as well, there was room for Korean criminal law to apply; but the flag State principle under international law barred the jurisdiction of the Korean court. In the end the Korean court took the view that Korea had no criminal jurisdiction and delivered a judgment dismissing the prosecution (Busan High Court, judgment of 16 December 2015).
It is not the case, however, that on the high seas the flag State principle is always the only thing at work. Piracy is regarded as the common enemy of mankind, so that universal jurisdiction is recognised, under which any State may seize and punish. Drugs, however, are different. Even as an offence committed on those same high seas, drug trafficking does not attract universal jurisdiction; States are to co-operate in suppressing it, but in principle by way of the consent and co-operation of the flag State.
Once the ship enters port, territoriality takes over
Yet even with narcotics taken on board on the high seas, the story changes the moment the ship carrying them comes into Korea. How, then, was the Gangneung case tried before a Korean court? The answer lies in Korea’s territorial sea — or, more precisely, in the fact that the ship entered a Korean port. This is because, even for a foreign ship, the moment she enters a Korean port there applies as it stands the territoriality principle of the Criminal Act, under which criminal law applies to nationals and foreigners who commit an offence within the territory of the Republic of Korea.
Innocent passage, and when a coastal State may still intervene
What, on the other hand, of a foreign ship that does not come into our ports but merely passes through the territorial sea? So long as this amounts to what is called innocent passage, the coastal State in principle refrains from exercising criminal jurisdiction over what happens on board that ship. This is in order to respect the freedom of navigation. Where necessary, however — where the consequences of the crime extend to the coastal State, where they impair the peace of the coastal State or the good order of the territorial sea, where the master or the flag State requests assistance, or in order to suppress the illicit traffic in narcotic drugs — the coastal State may intervene even in respect of a foreign ship in passage.
Concurrent jurisdiction: Korean ships, Korean seafarers and the Pescamar
What if a Korean ship or a Korean seafarer gives rise to a criminal problem in a foreign territorial sea or on board a foreign ship? In such a case, jurisdiction lies in the first instance with the State that holds territorial sovereignty over that sea. Our country’s jurisdiction does not thereby disappear, however. If the offender is a Korean seafarer, then under the nationality principle, and if a foreigner has committed an offence on board a Korean ship, then under the flag State principle, Korean criminal law may also apply and jurisdiction may also arise in the Korean courts. Jurisdiction will then be concurrent.
The leading example of concurrent jurisdiction is the Pescamar case of 1996. On board a foreign-flagged deep-sea fishing vessel operating on the high seas in the South Pacific, six Chinese crew members killed eleven people in all, including seven Korean crew. The ship’s State of nationality, the States of nationality of the offenders and of the victims, and Japan too, which first found the drifting vessel and opened the investigation — the jurisdiction of several countries became entangled all at once. Although the jurisdiction of several countries was concurrent, Korea tried them in the Korean courts for maritime robbery-murder and other offences, on the basis of the protective principle, under which Korean criminal law applies where a foreigner commits an offence against a national of the Republic of Korea outside the territory of the Republic of Korea. It is understood, however, that behind this lay no little diplomatic co-ordination with the countries concerned.
Conclusion
In this way, when something happens at sea, the nationality of the ship — the “floating territory” — is not the only absolute criterion. The boundaries of the sea, drawn where they cannot be seen, the nationalities of those involved and the character of the incident are important criteria too. Perhaps the sea, precisely because no boundary at all is visible upon it, is rather the space in which the greatest number of boundaries lie hidden.
K. M. Choi is a partner at Law Offices Choi & Kim, qualified in the Republic of Korea, with over ten years in shipping disputes, marine insurance and major casualties in Korean waters. He can be reached at kmchoi@choikim.com or on LinkedIn.
This article describes Korean law and practice in general terms and is not advice on the law of any other jurisdiction. The law is stated as at the date of the original Korean publication and may since have changed, and nothing here creates a lawyer–client relationship.