Dutch Supreme Court hands down judgment on the interpretation of ‘en route’ in the context of the MARPOL Convention

Dutch Supreme Court hands down judgment on the interpretation of ‘en route’ in the context of the MARPOL Convention

Arnold van Steenderen
22 January 2015

Recently, Dutch vessels and vessels arriving at Dutch ports have experienced heightened enforcement of environmental regulations. This has led to high fines in the past, for example when vessels are debunkering in Dutch ports. The case discussed in this article is another example of the stringent position the Dutch authorities usually take when it comes to enforcing (maritime) environmental regulations.

The International Convention for the Prevention of Pollution from Ships (MARPOL) and its Protocols and Annexes have been designed to regulate pollution in the maritime environment by ships from operational as well as accidental causes. Many states considered as major shipping nations have ratified the Convention and it Protocols.[1] MARPOL currently has 6 ‘technical’ Annexes, each of which deal with a specific substance or form of pollution. Annex I deals with oil pollution; Annex II with noxious liquid substances; Annex III with packaged harmful substances; Annex IV with sewage from ships; Annex V with garbage from ships and Annex VI with air pollution.

As said, Annex II regulates the discharge of noxious liquid substances.  Regulation of Annex II requires that when discharging “the ship is proceeding en route at a speed of at least 7 knots in the case of self propelled ships or at least 4 knots in the case of ships which are not self propelled”. This requirement is not unique to ANNEX II. For example, Annex V (garbage) also requires the vessel to be ‘en route’ when discharging. 

In the case before the Dutch Supreme Court, vessels flying the Dutch flag had washed their tanks and discharged substances as meant in Regulation 1(10) Annex II in the North Sea, within the Exclusive Economic Zone of the United Kingdom. When the vessels arrived in German territorial waters, the German Water Police (“Wasserschutzpolizei”) checked the logbooks of the vessels and made an official report of the alleged offence. 

As the vessels were flying the flag of the Netherlands, the shipowners were prosecuted in this jurisdiction. The Dutch Public Prosecutor took the stringent German view, namely that the shipowners were criminally liable as they were not ‘en route’ when discharging. In Germany, the MARPOL convention is implemented in such a way that vessels may not leave a port for the sole purpose to discharge. If the Public Prosecutor would get his way, vessels would always have to sail directly from one port to another, even when discharging residues.  

The question that needed to be answered by the Supreme Court was therefore whether the requirement for discharge in Annex II of a ship to be proceeding ‘en route’ is fulfilled when a vessel leaves the port for the sole purpose of washing tanks and therewith discharging noxious substances. 

The Supreme Court’s decision of 16 December 2014

The Supreme Court (as well as the District Court and the Court of Appeal) held that ‘en route' means that when discharging the ship must be sailing at the speed mentioned in Regulation 13. [2] Therefore, a ship may sail from a port for the sole purpose of washing its tanks and discharging noxious substances, provided the other requirements of MARPOL and the Annex have also been met. 

According to Regulation 1(6) Annex II “‘en route’ means that the ship is under way at sea on a course or courses, including deviation from the shortest direct route, which as far as practicable for navigational purposes, will cause any discharge to be spread over as great an area of the sea as is reasonable and practicable.

In its judgment, the Supreme Court refers to the opinion of the Advocate General of the Supreme Court.[3] To begin with the Advocate General, in accordance with Article 31 of the Vienna Convention, considered the ordinary meaning of ‘en route’ as defined above and concluded that being ‘en route’ only additionally requires that a vessel is at a course at a certain speed causing the discharge to be spread over as great an area of the sea as is practicable. The aim to spread the discharge over a large area of the sea would not be achieved by a requirement that vessels would have to sail without deviation from the shortest direct route from one port to another. Furthermore, the Advocate General notes that in light of the requirements to discharge at least 12 nautical miles from the shore and at a deep sea route, it would be impossible to wash the tanks if a vessel would sail from Rotterdam to Antwerp for example, if no deviation was allowed.

The Advocate General considered that there is no ‘subsequent practice’ of member states as provided for in Article 31(1) of the Vienna Convention on the Law of Treaties. One of the parties involved in the Dutch litigation had sought to rely on a judgment of the District Court of Hamburg, in which this German Court ruled that it was not allowed to leave a port for the mere purpose to wash and discharge cargo residues. However, the German Court explicitly noted that other jurisdictions bordering the North Sea apply a different interpretation of the Marpol Convention. Therefore, according to the Advocate General and the Supreme Court no ‘subsequent practice’ as in the Vienna Convention exists.  

As a final point, the Advocate General noted that a German proposal to add the text: “however a ship is not allowed to leave the port for the mere purpose to discharge cargo residues and to return to the same port directly” did not make it in the final text of the Annex, although the phrase was thoroughly discussed in the Correspondence Group.

By ruling in favour of the defendant, the Supreme Court ensured the common practice of vessels of sailing out for the sole purpose of discharging is continued. Vessels flying the Dutch flag can safely do so without facing criminal liability, provided the other requirements of MARPOL and the Annex are met.


[1] For a complete lists see: http://www.imo.org/About/Conventions/StatusOfConventions/Pages/Default.aspx.

[2] HR 16 December 2014, ECLI:NL:HR:2014:3633.

[3] The Advocate General delivers an advisory opinion before the judgment of the Dutch Supreme Court is rendered.