and the Intracoastal Waterway show distances in statute miles, the unit of measure you use on land. Most other charts use the “nautical mile” (1.15 statute miles), the length of one minute of latitude ...

you can store maps for every square mile of the Earth’s surface. [Erland] figured it was high time for digital maps to go nautical and built a tablet-like device to display charts while sailing.

For those charting a sentimental journey over land and sea, A Moment of Science would like to clarify a small point of navigation: the difference between a mile on land and a nautical mile.