The "doldrums" is a popular nautical term that refers to the belt around the Earth near the equator where sailing ships sometimes get stuck on windless waters.

A nautical mile measures distance and a knot measures speed.

A knot is one nautical mile per hour.

Iron is used in nautical construction.

A nautical mile is based on the circumference of the earth, and is equal to one minute of latitude.

A nautical mile is equal to 1.1508 statute miles.