The flag plays an important role in establishing public order at sea. It indicates the nationality of a vessel, and hence the State which is ultimately responsible for the vessel and which has jurisdiction over it on the high seas. The present work, which consists of the Master Memorial Lectures for 1977, is devoted to an examination of a number of questions of international law relating to the use of flags by vessels.

Judge Singh begins by examining the conditions different States lay down for granting their nationality to vessels. He identifies three distinct approaches: the national school, the “School of the Relaxed Law” (i.e. flags of convenience) and the balanced school. In spite of this diversity of approach, and the fact that a substantial proportion of the total world merchant shipping fleet is registered under flags of convenience, Judge Singh comes to the conclusion that the requirement imposed by art. 5 of the High Seas Convention (and reproduced in the current Informal Composite Negotiating Text of the Third United Nations Conference on the Law of the Sea), that there must be a “genuine link” between a State and a vessel having its nationality, is “now well-recognised and accepted”. Judge Singh is right, however, to point out, perhaps a little obliquely, that the current approach of the international community is to place less emphasis on the concept of a genuine link and instead to seek to ensure that a State exercises effective control over its vessels (see, for example, ILO Convention No. 147 concerning Minimum Standards in Merchant Ships of 1976 and art. 94 of the Informal Composite Negotiating Text).

Chapter II emphasises that only sovereign independent States (as opposed to entities which have not yet attained Statehood) are entitled to grant vessels the right to fly their flag. It is a pity that Judge Singh did not take the opportunity to discuss the question of whether vessels may sail under the flag of international organisations. Although this question has up to now been mainly a theoretical one—and concerned largely with the use of vessels by the UN for peace-keeping operations—it could become one of some practical importance, if, for example, the EEC were to establish its own fishery protection fleet.

The discussion on “Maritime Flag and State Responsibility” in Chapter III is a little sketchy. The situations in which State responsibility arises are enumerated (curiously there is no mention of responsibility for pollution), and the principles of law which govern State responsibility are set out in what one hopes is intended as a non-exhaustive list—since only two principles are mentioned. These are the sovereign equality of States and the duty to negotiate and seek peaceful settlement of disputes. As well as further elaboration of this topic, it would also have been useful if Judge Singh had included, either here or elsewhere, some consideration of questions of jurisdiction, which are, of course, closely bound up with the question of the ship’s flag.

The last, and by far the longest, chapter of the book deals with flag discrimination. Judge Singh identifies two broad types of discrimination—discrimination in relation to allotment of cargoes and discrimination in relation to the treatment of ships in