State immunity — Nature and scope — Applicability — Concept based on equality of States — People’s Republic of China resuming sovereignty over Hong Kong Special Administrative Region after 1 July 1997 — Whether action against organ of Chinese Government in Hong Kong impleading foreign State — Whether sovereign immunity having application inter-provincially — Basic Law of Hong Kong Special Administrative Region — “One country, two systems” principle — Crown immunity — Applicability — Nature — Concept based on inequality of ruler and ruled — Crown Proceedings Ordinance enacted in Hong Kong in 1957 — Effect on common law doctrine of Crown immunity — New constitutional order — Crown immunity after 1 July 1997 — Whether subsisting — Whether defendant owners of vessel Hua Tian Long entitled to assert Crown immunity — Whether forming part of Crown of People’s Republic of China — Whether submitting to Court’s jurisdiction — Whether waiving right to immunity — The law of the Hong Kong Special Administrative Region of the People’s Republic of China