How long does it take for China to go to the high seas?

when the land extends 2 nautical miles, it is the high seas. Generally, the speed of a cruise ship is slow, about 2 nautical miles per hour, which takes 1 hours to reach the high seas, while a faster passenger ship takes about 4 nautical miles per hour, which takes 4 hours to get out of the high seas.

In international law, the high seas refer to the domestic waters, territorial seas, archipelagic waters and ocean parts outside the exclusive economic zone that are not subject to the jurisdiction and control of any country's sovereignty.