What is the difference between a nautical mile and a statute mile? And what is a knot?
According to the Encyclopedia Britannica a nautical mile used to be based on the curvature of the earth and was approximately equal to one minute (arc segment) of latitude along a meridian (longitudinal line running from north to south). The British nautical mile was set to 6,080 feet while the US nautical mile was set to 6080.20 feet. However, in 1929 the nautical mile was redefined to exactly 1.852 km (approximately 6076.11549 feet) at an international conference held in Monaco, although the US didn't make the conversion until 1954. 

1 nautical mile = 1.1508 statute miles or 1.852 km.

A "knot" (speed measurement, not the kind you tie in your shoe laces) is equal to one nautical mile per hour. 

1 knot = 1.15 miles per hour.