Convert survey foot to nautical mile

The nautical mile is 1,852 m, defined so that it matches one minute of latitude: a degree of latitude is 60 nautical miles, which lets a navigator read distances straight off the edge of a chart. The knot is one nautical mile per hour, 1.852 km/h, and is the standard speed unit at sea, in the air and in weather reports. A gale, force 8 on the Beaufort scale, begins at 34 knots.

Gunter's chain of 1620 tied land measure to the acre: a chain is 66 ft or 100 links, 10 chains make a furlong (the length of a furrow), 8 furlongs a mile, and an acre is one chain by one furlong. Rods (16½ ft, a quarter chain) and chains still appear in US and Canadian deeds, and furlongs in horse racing. The US survey foot, 1200/3937 m, differs from the international foot by two parts per million, which adds up over a state; it was retired for new work on 1 January 2023, though survey data and legal descriptions in survey feet remain.