Degree Name

Doctor of Philosophy


Australian National Centre for Ocean Resources and Security (ANCORS)


The South China Sea is a semi-enclosed sea covering an area of approximately 3.5 million square kilometres and bordering China, Taiwan, and a number of other Southeast Asian States. As one of the busiest international sea lanes linking North East Asia with the rest of the world, securing maritime safety and the freedom of navigation in the South China Sea is essential for global trade. The region is also important from a military perspective. Military vessels and aircraft of regional and extra-regional countries transit through this maritime region, from the Pacific Ocean to the Indian Ocean and the Middle East. However, clashes between littoral States over territorial sovereignty and associated maritime claims in the South China Sea have become commonplace. So too have disputes over differing interpretations of international law provisions relating to navigation and maritime safety in various maritime jurisdictional zones. Indeed, these factors mean that the South China Sea ―ranks among the most geographically and geopolitically complex ocean spaces in the world.

All States surrounding the South China Sea (except Taiwan) are parties to the United Nations Convention on the Law of the Sea (LOSC). However, despite the LOSC having entered into force in 1994, many regional disputes remain unresolved, making the South China Sea ripe for potential conflicts. Apart from the LOSC, there are a number of international conventions governing the safe passage of vessels and aircraft on and over the sea. These include the International Regulations for Preventing Collisions at Sea, the International Convention for the Safety of Life at Sea, and the Convention on International Civil Aviation. Nevertheless, in an effort to protect their interests and strengthen their maritime claims in the region, littoral and non-littoral States have strengthened the presence of their military and law enforcement vessels and aircraft (sovereign immune vessels and aircraft). In doing so, multiple clashes have occurred over the past 20 years, with such clashes showing no sign of abatement.

Sovereign immune vessels and aircraft operating at sea should act in accordance with the international law of the sea and air. However, inconsistencies and ambiguities exist in the navigational regimes of the LOSC, the practice of States, as well as in the prevailing international law. Due to the geopolitical complexity of the South China Sea, additional naval and law enforcement vessels including surface combatants, submarines, and aircraft are likely to be operating in this region in the near future. With this concentration of military and law enforcement assets, the potential for maritime incidents involving sovereign immune vessels and aircraft in the South China Sea will undoubtedly increase.

To address the problems arising from the passage of these types of vessels and aircraft, a number of solutions have been devised. They include binding and nonbinding regional instruments, bilateral agreements, unilateral initiatives, as well as guidelines proposed by regional governments and academic and policy forums. However, these efforts have had very limited success.

This thesis provides an analysis of the international legal regime and geopolitical issues surrounding the passage of sovereign immune vessels and aircraft in the South China Sea. International law principles, regional efforts, and the practice of South China Sea littoral States regarding the passage of such vessels and aircraft in different maritime zones of jurisdiction are critically analysed. Following on from this, ambiguities and gaps in the current international legal framework and regional efforts are identified. The thesis then provides potential options for clearer, more responsible navigational regimes for sovereign immune vessels and aircraft in the South China Sea.