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Problems Associated with Navigation
Information
As you have learned, navigation is an art and a science. Our early
navigators experienced the same problems that face the modem
navigators.
There are three major problems of navigation that must
always be addressed. These problems are:
How to determine position
How to determine the direction to get from point A to point B
How to determine the distance between points, the time it will
take, and the speed as the navigator proceeds
Determining
Position
Of the three problems facing the navigator, the most basic and also the
most important is determining position. The ship’s position must be
known to safely and accurately direct the movements of the ship.
The term position refers to a known point on Earth. QMs refer to a
position as a fix. It may also be qualified by an adjective such as
estimated and dead reckoned.
Measuring
Direction
Direction is the orientation of a line drawn or imagined joining two
positions without any regard to the distance between them. Direction on
charts is measured in angular units using a polar coordinate system (a
coordinate system based on the North Pole and South Pole). The
reference used is normally true north.
Figure 1-3
shows a line
drawn between
two positions.
The direction
may be
determined
from the
compass rose.
Direction is
measured from
000° T through
360° T.
Figure 1-3. Compass rose.
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