/ˈnæʃənl ˈwɔtərz/ – Phrase
Definition: thủy phận quốc gia.
A more thorough explanation: National waters refer to the maritime areas that are under the jurisdiction of a particular country, typically extending up to 12 nautical miles from the baseline of the country’s coast. These waters are considered part of the sovereign territory of the country and are subject to its laws and regulations.
Example: The fishing vessel was found operating illegally within the nation’s national waters.