126 seamanship secrets
- Time the light period three times in a row. For example, if a navaid
fl ashes every 4 seconds, verify three successive 4-second intervals.
When sighting a midchannel light with its characteristic Morse (A)
pattern, verify three consecutive sets of long-short fl ashes.
SEA-CRET TIP
X Check the Coast Guard Light List to fi nd the sound-signal char-
acteristic of any major light structure. Look in the far right column for
the interval in seconds between successive blasts. Time the interval
between blasts and compare it with the Light List time. Times should
match within 0.1 second.How to Use S.T.O.P. for Easy Orientation
On the water aft er sunset, our perceptions change. Height and distance become
diffi cult to judge. It’s a challenge to orient what we see on the chart to what we
see on the water. Most of us are content
to anchor or moor after dark and be
done with it, but nighttime sailing off ers
peace and quiet, cooler summertime
temperatures, and a special beauty all its
own. Below are helpful tips for navigat-
ing aft er dark.
PREPARATIONS FOR
NAVIGATING AT NIGHT
With your highlighter, mark each light
structure along your route on the chart.
Tape the area of transit and tape over
the aids to navigation (see Chapter 2
on marking charts). Draw a small circle
around each light structure. Write the
name, color, and light period alongside.
This simplifies the full description by
showing only the most important iden-
tifi cation information. For example, the full charted description of R “22” fl R 4
sec 3M 16 ft could be simplifi ed to “22” R4.
Supplies and Tools
Needed for Navigating
at Night
X parallel rulers or protractor (for
measuring courses and bearings
between ATONs)
X handheld spotlight (one million
or greater candlepower, to pick
up an ATON at night)
X handbearing compass (with
night-light)
X small fl ashlight with red or blue
lens (to prevent night blindness)
X highlighter and black felt-tip
marker (for annotating your chart)
X Scotch Magic Tape or dull fi nish
tape that accepts writing