William Rodman Sellers (Sellers) was the owner and master of the Nimbus, registered in the Port of Valletta, Malta. Sellers permitted the Nimbus to leave Opua, New Zealand, for an overseas port without obtaining clearance from the New Zealand authorities. The Director of Maritime Safety required pleasure craft to carry a radio and emergency locator beacon equipment as a minimum before departing a port in New Zealand for any place outside New Zealand. Sellers did not seek the required clearance.

Sellers was therefore prosecuted for a breach of the Maritime Transport Act 1994 and convicted in the District Court. Sellers appealed to the High Court. The High Court dismissed his appeal but granted him leave to appeal to the Court of Appeal.

Sellers argued that:

My maritime art is based on the mystery of the sea. It is religious to me, being alone, simple and strong with the sea - not with radios - the radio has stuffed everything ... but the mystery of the ancient sea will outlast man. I am protesting on religious grounds to attempts to restrict free and private movement on the open sea.

Held: Appeal allowed.

The Court of Appeal quashed Sellers' conviction and sentence. The Director of Maritime Safety set minimum requirements not permitted by international law. Sellers should not be held to be committing an offence for not complying with requirements set without lawful authority.

A port State has no general power to impose unilaterally its own requirements on foreign ships relating to their construction, safety, other equipment, and crewing if the requirements are to have effect on the high seas. Any requirements cannot go beyond those generally accepted, especially in maritime Conventions and regulations. For over a century, New Zealand Courts have made it plain that legislation regulating maritime matters should be read in the context of the international law of the sea and, if possible, consistently with that law (R v Dodd (1874) 2 NZCA 598; Re The Award of the Wellington Cooks and Stewards' Union (1906) 26 NZLR 394 (Full Court)). In R v Keyn (1876) 2 Ex D 63, 85, Sir Robert Phillimore stated that 'it is an established principle as to the construction of a statute that it should be construed, if the words will permit, so as to be in accordance with the principles of international law'.

Sellers' objection was based on the principle of the freedom of the high seas. The freedom of the high seas, including the freedom of navigation, is one of the longest and best-established principles of international law (UNCLOS, art 87.1). This principle applies to New Zealand as it is a party to UNCLOS.

When a ship is on the high seas, the flag State has exclusive jurisdiction over the ship, and the freedom of navigation is subject only to 'exceptional cases expressly provided for in international treaties' (art 92.1). The exceptions relate to the recognition of the freedoms of the high seas (1982 Int Leg Mat 1261), which are to be exercised by all States with due regard for the interests of other States in their exercise of the freedoms (art 87.2).

While a flag State has exclusive jurisdiction over a ship flying its flag on the high seas (The case of the SS Lotus: France v Turkey PCIJ 1927 Series A No 10 [64]), it does not follow that a State can never in its own territory exercise jurisdiction over acts which have occurred on board a foreign ship on the high seas (ibid [65]):

there is no rule of international law prohibiting the State to which the ship on which the effects of the offence have taken place belongs, from regarding the offence as having been committed in its territory and prosecuting, accordingly, the delinquent.

The 'effects of the offence' wording might support a contention that the Director of Maritime Safety must be able to exercise powers to discharge the responsibilities in providing search and rescue services in the vast area of the Pacific Ocean. Article 98.2 codified the duty of mariners to render assistance to those in peril at sea and the duty of coastal States to:

promote the establishment, operation and maintenance of an adequate and effective search and rescue service regarding safety on and over the sea and, where circumstances so require, by way of mutual regional arrangements [to] co-operate with neighbouring States for this purpose.

However, art 98.2 does not recognise or confer any rights or powers on coastal States in support of the responsibility.

In The case of the SS Lotus, the Court decided that Türkiye had criminal jurisdiction over the French officer of the watch on the French mail steamer, the Lotus, which was in a collision with a Turkish vessel in which Turkish nationals perished. The international community disagreed, as seen in the preparation of UNCLOS (art 97) and other Conventions.

A State of registration can issue such flags in an exercise of its freedom to confer nationality on ships (art 91). However, there was a concern that vessels flying so-called 'flags of convenience' were not meeting their obligations (see the Convention concerning Minimum Standards in Merchant Ships 1976). These obligations were to exercise effectively its jurisdiction and control in administrative, technical, and social matters over ships flying its flag (art 94.3). Each State must conform to generally accepted international regulations, procedures, and practices, and take any steps necessary to secure their observance (art 94.5).

UNCLOS expressly denies the power of a coastal State in respect of a foreign ship once it has left port and is passing through the territorial sea to the high seas (arts 21.1 and 21.2). An inference is the lack of unilateral national power to create safety obligations for foreign ships on the high seas (ibid). Article 21.2 also limits the laws of coastal States on foreign ships' design, construction, crewing, and equipment to give effect to generally accepted international rules or standards.

Article 234 has several unusual features. It is one of the few provisions of UNCLOS negotiated directly between the States involved - Canada, the USSR, and the United States - and incorporated into the various texts without opposition. It picks up a theme of marine pollution with its reference to rare or fragile ecosystems (art 194). It is the only provision in Part XII on protecting and preserving the marine environment which accords a coastal State the right to adopt and enforce its own non-discriminatory laws relating to marine pollution within its exclusive economic zone. A broader significance of art 234 is the great reluctance to recognise or confer coastal State powers to impose national law on foreign vessels on the high seas (even within the country's exclusive economic zone) to protect coastal interests.

There are certain obligations imposed on States which establish particular requirements to prevent, reduce, and control the pollution of the marine environment as a condition of entry to their ports or internal waters or for a call at their off-shore terminals (art 211.3). Article 211.3 evidences the limit of subject matter and the limit to rules relating to entry, indicating no broader principle of port State power to protect national interest. Article 211 also gives major emphasis to agreed international rules and standards and, while allowing certain State laws relating to: (a) the territorial sea, requires that they do not hamper the right of innocent passage; and (b) the exclusive economic zone, requires that they conform and give effect to generally accepted international rules and standards established through the competent international organisation or general diplomatic conferences.

Article 218 does not support the proposition that coastal States have powers to extend unilateral requirements protecting an important State interest to foreign ships on the high seas. The provision enables the coastal State to investigate and, if appropriate, institute proceedings in its Courts in respect of a vessel voluntarily within one of its ports relating to discharge from that vessel outside its internal waters, continental shelf, or exclusive economic zone in violation of applicable international rules and standards established through the competent international organisation or general diplomatic conference. Further, the provision makes it plain that the discharge may have had nothing to do with the port State - it may have occurred in another State's internal waters (art 220).

The emphasis is on establishing rules by international processes and on the duty of the flag State to enforce them (see also arts 216 and 217). Port States may have a role in respect of foreign vessels. They are obliged in certain circumstances to prevent a foreign vessel within one of their ports from sailing, if the vessel violates applicable international rules and standards relating to seaworthiness or threatens damage to the marine environment (art 219; see also safeguards in arts 223-233).