You're talking of the nautical mile. It's used globally in the marine industry. The nm is 1.1miles or 1.85km. And it's based on 1 arcminute of the circumference

You're talking of the nautical mile. It's used globally in the marine industry. The nm is 1.1miles or 1.85km. And it's based on 1 arcminute of the circumference of the Earth.