Gigameter (Gm): A gigameter is equal to one billion (10^9) meters. It is used for long-distance measurements, such as the size of celestial objects or interplanetary distances.
There isn't a widely accepted international standard for a "nautical league." The nautical mile (nmi) is the more common and internationally recognized unit of measurement for distances at sea. A nautical mile is approximately equal to one minute of latitude along a meridian, and it is used worldwide for maritime and aviation navigation.
In some regions, historical or localized variations of the league may have been used in the past, but these are not part of the modern international system of measurement. It's important to note that such variations can differ by country and even within different historical periods.
For precise and internationally recognized measurements in maritime and aviation contexts, the nautical mile is the preferred unit of distance. One nautical mile is equal to approximately 1.852 kilometers or 1.15078 statute miles (land miles).