chart and publication secrets 13
Ranges Lead You to Safety
Among the mariner’s best friends are ranges, either those that are man-made
or those that form by the natural coincidence of charted objects. Use ranges
whenever possible to increase the safety of navigation, to position your vessel,
or to check your compass.
Natural ranges are everywhere—a charted church spire over a point of land;
a bold rock in front of the highest elevation of a more distant island; a bell buoy
directly in front of a lighthouse; and so forth. Once you start looking for them,
you’ll spot natural ranges all around your boat. Any range like this can give you
the most accurate line of position on earth, as we’ll see in Chapter 4. For now,
though, let’s talk about man-made ranges.
A Coast Guard–established range usually comprises two fixed, lighted
structures placed at the far end of a channel. Th e front light (i.e., the light nearer
the channel) is shorter than the rear (more distant) light. When you align the
lights so that the nearer one is directly beneath the farther one, you are on
range—i.e., you are in the center of the channel.
When the lights don’t line up, you are said to be off range. If you want to
return to the center-of-channel, you must know which way to turn. Follow
these simple rules to fi nd out where you are and how to stay on range:
If the range lights are over your bow, follow the nearer, shorter object or
light to get back on range.
If the front object is to the left of the back object, turn left to get back on range.
If the front object is to the right of the back object, turn right to get back on
range.
If the range lights are over your stern, follow the more distant, taller
object or light to get back on range.
If the back object is to the left of the front object, turn left to get back on range.
If the back object is to the right of the front object, turn right to get back on range.When you are steering toward a range, the two structures will line up (center). When you
are off range to the left (left on illustration), turn right to get back on range, when you are
off range to the right (right portion of illustration), turn left to get back on range.