While on the high seas, only UK law (i. e. flag State law) applies. While in the national waters of another State, UK law applies on board, but may be overridden by the law of the coastal State or port State in certain cases, e. g. in customs, sanitation, pollution, immigration and health and safety matters, and where any crime is committed under the law of the coastal or port State.
What laws are UK ships, and seafarers on board them, subject to when they are outside UK waters?
