Nautical Miles

A nautical mile is the standard unit of distance used at sea, equal to exactly 1,852 metres. It is based on the Earth’s geometry: one nautical mile is approximately one minute of latitude, making it well suited to chart work, position fixing, and ocean navigation.

For boaters, nautical miles are the basis for estimating passage distance, fuel range, time under way, and safe arrival windows. Boat speed is normally expressed in Knots, meaning nautical miles per hour, while electronic navigation from GPS and route calculations in Weather Routing commonly use nautical-mile distances to compare course options and ETAs.

In PredictWind, routes, GRIB overlays, tracking positions, and offshore passage plans are interpreted against nautical-mile distances. Whether checking a coastal hop or a multi-day passage in the Offshore App, understanding nautical miles helps you relate forecast timing, boat speed, currents, and remaining distance more accurately.