In navigation, dead reckoning is determining your current position based on your last known location. Because canoes and kayaks seldom leave sight of shore, you mainly use it during crossings, along featureless shorelines, in foggy conditions or to give you an estimated location between fixes. You can use the same technique to estimate your future position. To do dead reckoning, start with a known location, such as a navigation fix, marked on your chart or map. From that point, advance a line along your known course a distance based on your speed and the time traveled using the formula shown below. Current or wind can affect your DR; during critical…