§ 6.0 What This Chapter is About. Discussions of flag states often bring emotional, economic and political responses,1 which tend to be conflated with flag state law and confuse both owner and shipmaster.2 Here, we define “ship” and “master” to establish a common understanding of the terms among the states. Then, we look at the law of the flag states and governance of the shipmaster.3 This chapter is not about the procedures for registering a vessel in a state, which is well covered elsewhere.4 Subsequent chapters deal with the master and laws in territorial seas, ports, economic zones, internal waters, straits and archipelagic waters as defined in UNCLOS 1982,5 and of this book provides redactions of the statutes governing the master in most flag states having more than 49 vessels registered.6 Approximately 95% of the cargo movements in international trade are by ships associable with 21% of the flag states.7 The owners in these states maintain vessels flying either a national flag co-existent with the nationality of the owner, a closely-related flag or a captive flag8 or flags foreign to the state.9 The dominance of the registry state’s laws is so great that the development of the law and its evolution to the current situation is helpful in understanding the master’s positions. To do so, one must at the outset distinguish between the nationality of a ship and the registry state or, colloquially, the flag state of a ship.10 The notion that a ship has a nationality in law came about in the early part of the nineteenth century.11 However, nationality and registry were and are not necessarily the same, although registry is a strong indicant of nationality.12 The criteria for determining nationality, which became well-known in the 1820s, were the nationality of the owner, the nationalities of those aboard and the state of registration.13 The concept has been criticized14 and at least one attempt has been made to re-nominate it.15 However, the term is useful.16 Articles 5-7 of the Convention on the High Seas 1958 and its inclusive Articles 91-92 UNCLOS 198217 refer to the nationality of ships. The difficulty, as alluded to infra, lies in trying to relate the nationality of a vessel with a counterpart legal or natural person at law as the owner for differing conceptual purposes, presumptions, legal natures and consequences of each despite their comparative similarities.18 For example, Articles 91 and 92(2) of UNCLOS 1982 do not allow a ship to be stateless19 but also do not allow it to have multiple states of registry. A natural person, however, may be stateless or may have multiple states of citizenship.20 The notion of nationality of vessels, therefore, is directed at the allocation of control, jurisdiction and diplomatic protection of a vessel and to put persons interested in the vessel under the authority of a state.21 The term is currently shorthand for the connection between the registry state and its jurisdiction22 to the end that order on vessels on the high seas can be maintained.23 This does not mean, however, that a state has unfettered powers to confer nationality on a ship, as The Muscat Dhows case24 would imply.